Durable magnet wires and lubricating fluids for electric and hybrid vehicle applications

ABSTRACT

The present disclosure relates to a driveline for an electric or hybrid-electric vehicle including an electric motor with an insulated magnet wire and a lubricating and cooling fluid configured to maintain the durability of the magnet wire.

TECHNICAL FIELD

The present disclosure relates to drivelines for electric orhybrid-electric vehicles including an electric motor with an insulatedmagnet wire and lubricating compositions in contact with the insulatedmagnet wire effective to provide improved durability of the insulatedmagnet wire.

BACKGROUND

Electric and hybrid-electric vehicles may contain a power source (atraditional combustion engine, such as a gasoline or diesel engine,and/or a battery source coupled to an electric motor) combined with adriveline and/or transmission for transferring power to the wheels ofthe vehicle. The driveline and/or transmission may include an electricmotor and/or a gear reduction unit coupled to the wheels. In someapplications, a lubricant is provided containing a lubricant compositionfor lubricating both the electric motor and/or gearing in the drivelineor a power gear reduction unit.

In electric and hybrid-electric vehicle applications, the lubricatingfluid may be in contact with wires or parts of the electric motor aswell as parts of a driveline, transmission, and/or traditionalcombustion engine gear reduction unit. As such, suitable fluids musthave applicability for very distinct types of vehicle componentry. Forexample, the lubricating fluid may be in contact with magnet wires foundin the motor stator as well as the gears in the mechanical portions ofthe drivelines or transmission. Suitable fluids for these applications,therefore, not only must have traditional lubricating properties, butalso need to be compatible with electronic componentry as well asinsulation layers of such electronic components.

Prior lubricants for transmissions typically required low friction andanti-wear capability, stability against heat and oxidization, as well asdetergency and dispersancy capabilities. In order to achieve suchcharacteristics, prior lubricants generally included a base oil and avariety of additives such as anti-oxidants, detergents, dispersants,anti-wear agents, rust inhibitors, metal deactivators, frictionmodifiers, antifoam agents, seal swell agents, and/or viscosity indeximprovers to suggest but a few conventional lubricant additives.

To be suitable for electric components, the fluids generally need toprovide good lubricating performance, good electrical conductivity,and/or good cooling performance as well as being compatible withinsulation coatings of any electrical wires or other componentry thatthe fluid may contact. Often, one or more of the desired propertiesneeded for electric and hybrid-electric applications is compromised dueto the collection of additives commonly used in such traditionallubricating fluids; thus, prior lubricating fluids may be unsuitable forelectric or hybrid-electric vehicles for one or more reasons. Forinstance, some traditional lubricant packages may have low electricalconductivity but then have poor thermal conductivity (providing poorcooling performance), which would be undesired for electric or hybridapplications. Other traditional lubricant packages may have high thermalconductivity (providing good cooling capability) but then have poorelectrical conductivity, which also would be undesired for the electricor hybrid applications. Yet other traditional lubricant compositions mayattack or breakdown insulation provided on electrical wires orelectrical components and, over time, degrade the performance of suchelectrical componentry as evidenced by a poor or degrading wirebreakdown voltage after fluid aging. Thus, prior conventional drivelinelubricating fluids do not necessarily provide desired performance forthese unique applications in the context of electric or hybrid-electricdrivelines.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a plot of magnet wire breakdown voltage relative to metalcontent of a lubricating and cooling fluid and mol percent of estergroups in a base oil system of that lubricating fluid.

SUMMARY

The present disclosure relates to a driveline for an electric orhybrid-electric vehicle. In one approach or embodiment, the drivelineincludes an electric motor including an insulated magnet wire having aninsulation coating thereon with a thermal rating of about 190° C. toabout 210° C. and a lubricating and cooling fluid in contact with theinsulation coating of the insulated magnet wire of the electric motor.In some aspects of this embodiment, the lubricating and cooling fluidincludes a detergent system providing at least about 50 ppm metal to thefluid and a base oil system including a first base oil of lubricatingviscosity blended with an ester base oil. In approaches, the base oilsystem may also include at least about 20 weight percent of the esterbase oil, and has a ratio of the metal provided by the detergent systemto mol percent of ester groups in the base oil system of the lubricatingand cooling fluid of about 70 or less.

In other approaches or embodiments of the driveline, the driveline mayalso include a number of optional embodiments in any combination. Theseoptional approaches or embodiments of the driveline may include one ormore of the following: wherein the insulation coating of the magnet wireincludes one or more layers and wherein the layer in contact with thelubricating and cooling fluid includes a polyamide, a polyimide, apoly(amide/imide), combinations thereof, blends thereof, or copolymersthereof; and/or wherein the magnet wire has an AWG gauge of 14 to 30 ;and/or wherein the magnet wire is copper; and/or wherein the insulatedmagnet wire in contact with the lubricating and cooling fluid has abreakdown voltage of about 10,000 volts or higher; and/or wherein theester base oil includes a branched diester; and/or wherein the brancheddiester is a reaction product of one or more dicarboxylic acids havingan internal carbon chain length of 6 to 10 and one or more alcoholshaving a branched carbon chain length of 6 to 12 carbons; and/or whereinthe ester base oil includes a monoester and/or a diester having thestructure of Formula I:

wherein R₁ is a carbon chain having m-2 carbons with m being an integerfrom 6 to 10, R₂ and R₃ are the same or different and include C8 to C20linear or branched alkyl chains, and n is an integer of 0 or 1; and/orwherein n is 1 and R₂ and R₃ are the same or different and include C8 toC10 branched alkyl chains; and/or wherein the ester base oil is selectedfrom a dibasic ester based on bi(6-methylheptyl)adipate; a dibasic esterbased on bis(8-methylnonyl) adipate; or a linear monoester having about16 to about 18 carbons in an acid moiety thereof and about 20 linearcarbons in an alcohol moiety thereof; or combinations thereof; and/orwherein the detergent system includes alkali or alkaline metal salts ofphenates, sulfonates, calixarates, salixrates, salicylates, carboxylicacids, sulfurized derivatives thereof, or combinations thereof; and/orwherein the alkali or alkaline metal includes calcium, magnesium,potassium, sodium, lithium, barium, or mixtures thereof; and/or whereinthe detergent system provides no more than 800 ppm of the metal; and/orwherein the first base oil of the base oil system is a mineral orsynthetic base oil; and/or wherein the first base oil of the base oilsystem is a polyalphaolefin.

In another approach or embodiment of this disclosure, the driveline fora hybrid or hybrid-electric vehicle includes an electric motor with aninsulated magnet wire having an insulation coating thereon and whereinthe insulation coating include a polyamide, a polyimide, apoly(amide/imide), a combination thereof, blends thereof, or copolymersthereof combined with a lubricating and cooling fluid in contact withthe coating of the insulated magnet wire of the electric motor. Inaspects of this embodiment, the lubricating and cooling fluid mayinclude a detergent system providing at least about 50 ppm metal to thefluid and a base oil system including a first base oil of lubricatingviscosity blended with an ester base oil and wherein the base oil systemincludes at least about 20 weight percent of the ester base oil.

In other approaches or embodiments of the driveline described in theprevious paragraph, the driveline may also include a number of optionalembodiments in any combination. These optional approaches or embodimentsof the driveline may include one or more of the following: a ratio ofthe metal provided by the detergent system to the mol percent of estergroups in the base oil system of about 70 or less; and/or wherein theinsulation coating of the magnet wire has a thermal rating of about 190°C. to about 200° C.; and/or wherein the insulated magnet wire in contactwith the lubricating and cooling fluid has a breakdown voltage of about10,000 volts or higher; and/or wherein the ester base oil includes abranched diester; and/or wherein the branched diester is a reactionproduct of one or more dicarboxylic acids having an internal carbonchain length of 6 to 10 and one or more alcohols having a branchedcarbon chain length of 6 to 12 carbons; and/or wherein the ester baseoil includes a monoester and/or a diester having the structure ofFormula I:

wherein R₁ is a carbon chain having m-2 carbons with m being an integerfrom 6 to 10, R₂ and R₃ are the same or different and include C8 to C20linear or branched alkyl chains, and n is an integer of 0 or 1; and/orwherein n is 1 and R₂ and R₃ are the same or different and include C8 toC10 branched alkyl chains; and/or wherein the ester base oil is selectedfrom a dibasic ester based on bi(6-methylheptyl)adipate; a dibasic esterbased on bis(8-methylnonyl) adipate; or a linear monoester having about16 to about 18 carbons in an acid moiety thereof and about 20 linearcarbons in an alcohol moiety thereof; or combinations thereof; and/orwherein the detergent system includes alkali or alkaline metal salts ofphenates, sulfonates, calixarates, salixrates, salicylates, carboxylicacids, sulfurized derivatives thereof, or combinations thereof and/orwherein the alkali or alkaline metal includes calcium, magnesium,potassium, sodium, lithium, barium, or mixtures thereof and/or whereinthe detergent system provides no more than 800 ppm of the metal.

In yet further approaches or embodiments of this disclosure, methods oflubricating a driveline and electric motor are provided. In aspects, themethods include lubricating the driveline and/or or electric motor withany embodiment of the lubricating and cooling fluids described hereinwherein the insulated magnet wire of the electric motor is in contactwith the lubricating an cooling fluid.

In yet other approaches or embodiments, the use of any embodiment of thelubricating and cooling fluids herein is described for lubricating anyembodiment of the drivelines of a hybrid or hybrid-electric vehicledescribed herein. In approaches, the use includes contacting at leastthe insulated magnet wire of the electric motor with any embodiment ofthe lubricating and cooling fluids herein for achieving the improvedbreakdown voltage as described above.

DETAILED DESCRIPTION

The present disclosure describes systems including magnet wires withlubricating and cooling fluids suitable for electric and/orhybrid-electric vehicle applications, and in particular, drivelinesand/or transmissions thereof where the lubricating and cooling fluidscontact the electric and/or hybrid-electric motors and componentsthereof such as the insulated magnet wires. The fluids herein exhibitnot only good lubricating properties, but also good electricalproperties and are compatible with insulation coating layers of themagnet wires found in the electric motors of such vehicle applications.

In some aspects, the present disclosure includes a system with adriveline for an electric or hybrid-electric vehicle where the drivelineincludes at least an electric motor with one or more insulated magnetwires. Each magnet wire has an insulation coating thereon with a thermalrating of about 190° C. to about 210° C. In approaches, the insulationcoating of the magnet wire may include one or more layers and wherein atleast the outer layer in contact with the lubricating and cooling fluidincludes a polyamide, a polyimide, a poly(amide/imide), combinationsthereof, blends thereof, or copolymers thereof

The driveline further includes a lubricating and cooling fluid incontact with the insulation coating of the magnet wire from the electricmotor. To provide compatibility with the insulation coating of themagnet wire, the lubricating and cooling fluid includes a selectcomposition including, but not limited to, a detergent system providingat least about 50 ppm metal to the fluid and a select base oil systemincluding a first base oil of lubricating viscosity blended with anester base oil. In some embodiments, the base oil system includes atleast about 20 weight percent of the ester base oil, and the lubricatingand cooling fluid has a ratio of metal provided by the detergent systemto mol percent of ester groups in base oil system of about 70 or less.With such fluids and magnetic wire combinations, the driveline systemsherein provide for the insulated magnet wire, when in contact with thelubricating and cooling fluid, to have a breakdown voltage of 10,000volts or higher after aging (as described more below). As discussedfurther below and as shown in FIG. 1 , lubricating and cooling fluidshaving such unique relationship of metal and ester content surprisinglyprovides good compatibility with magnet wire insulation coatings toprovide the high levels of breakdown voltage and durability to themagnet wire insulation upon aging in the fluids.

Drivelines for electric and/or hybrid-electric vehicles all utilizeelectric motors. One feature to the electric motor is the magnet wirethat is used to interchange electrical energy with magnetic energy. Asgenerally understood, electric motors include one or more coil(s) of themagnet wire that become an electromagnet when current passes through it.The electromagnet interacts with a permanent magnet, causing the coil tospin and thereby powering the motor. As electric motors operate, theygenerate heat and need to be lubricated and/or cooled. Thus, fluidscommonly used in internal combustion engines are often employed forsimilar cooling and lubricating purposes in electric motors. However, asexplained in the Background, prior lubricants for internal combustionengines may not be compatible with the insulation coatings found onmagnet wires as prior fluids tend to degrade the magnet wire coatingupon aging as evidenced by a low measured breakdown voltage.

As used herein, breakdown voltage is measured as the DielectricBreakdown AC Voltage specified in Sections 70 to 76 of ASTM D1676-17using the parameters as specified therein for 6 wire twists. The wiresare twisted and prepared for this evaluation pursuant to section 3.8.4of ANSI NEMA Magnet Wire standard 1000 -2018, and wire aging isperformed by immersing the twisted wires in about 75 to about 100 gramsof the test fluid for about 5 days (120 hours) at about 150° C. asfurther described below in the Examples. Water may be added to increasethe severity of the testing. Breakdown voltage may be measured using aMegger 1525 insulation resistance tester or equivalent.

Magnet Wires:

The driveline systems herein include at least one electric motor and alubricating and cooling fluid. Each electric motor includes one or morecoils of magnet wires. In embodiments, the magnet wire for the electricmotors and drivelines of the systems herein may be a 14 to 30 AmericanWire Gauge (AWG) copper or aluminum wire that is round, rectangular, orother shape covered by one or more insulation layers. The insulationlayer, and in particular the outer insulation layer of the electricwire, will come into contact with the lubricating and cooling fluids ofthe vehicle driveline. Magnet wires often include polymer insulationlayers that may include one or more distinct polymer compositions. Thesepolymers may be blended in a single layer or such polymers may bemultiple concentric layers about the wire.

In embodiments, magnet wire insulating coatings may include polymers orcopolymers in single or multiple coating layers of polyvinylalcohol-formaldehyde-polyvinyl acetate; polyurethane; polyamide;polyester; polyester-polyimide; polyamide-polyimide; and/or polyimides,or combinations thereof. Preferably, the magnet wires of the drivelinesand electric motors of the systems herein include one or more coatinglayers of a polyamide, a polyimide, a poly(amide/imide), apolyamide-imide, or combinations thereof, blends thereof, or copolymersthereof. Insulated magnet wires have a thermal rating class, and thewires of the present disclosure typically have at least a 190° C.thermal rating and, in some instances, a 190° C. to 210° C. thermalrating, and most preferably, at 200° C. thermal rating. The outersurface of the magnet wire insulation coating contacts the lubricatingand cooling fluids of the drivelines herein.

Lubricating and Cooling Fluids for the Driveline

The drivelines herein include not only the electric motors andassociated magnet wires thereof as noted above, but also a lubricatingand cooling fluid with a select detergent system and a select base oilsystem configured for magnet wire durability. These components ascombined uniquely provide the magnet wires with a high durability uponaging as measured by a high breakdown voltage. Each feature of the fluidwill be described in more detail below, but in general the detergentsystem provides at least about 50 ppm metal to the fluid (preferably atleast 100 ppm metal, at least about 150 ppm metal, or at least about 200ppm metal) and the base oil system includes a select blend of one ormore first base oils of lubricating viscosity combined with an esterbase oil. In some embodiments, the fluids herein may have (i) at leastabout 20 weight percent of the ester base oil in the base oil system and(ii) the lubricating and cooling fluid has a ratio of metal provided bythe detergent system relative to the mol percent of ester groups in thebase oil system of about 70 or less as generally shown in the chart ofFIG. 1 to achieve the high breakdown voltage durability.

The Detergent System: The lubricant and cooling fluids herein include aunique detergent system providing select amounts of metals, such ascalcium, magnesium, potassium, sodium, lithium, barium, or mixturesthereof (preferably calcium), and in some embodiments, select amounts ofsuch metals relative to the mol percent of ester groups of the base oilsystems in order to provide high breakdown voltage of the drivelinemagnet wires.

In embodiments, the detergent system includes detergent additives suchas alkali or alkaline metal salts of phenates, sulfonates, calixarates,salixrates, salicylates, carboxylic acids, sulfurized derivativesthereof, or combinations thereof. Preferably, the detergents are phenateor sulfonates, and most preferably sulfonates. Suitable detergents andtheir methods of preparation are described in greater detail in numerouspatent publications, including U.S. Pat. No. 7,732,390 and referencescited therein, which are incorporated herein by reference. The lubricantcompositions herein may include about 0.1 to about 5 weight percent ofdetergent additives, and in other approaches, about 0.15 to about 3weight percent, and in yet other approaches, about 0.15 to 1.0 weightpercent of detergent additives.

As noted above and in some approaches, the detergent system providesselect amounts of metals, and in some approaches, select amounts ofcalcium and/or magnesium. For instance, the detergent system provides anamount of metal that is greater than about 50 ppm metal based on thetotal lubricating composition, and in other approaches, about 50 ppm toabout 800 ppm metals, about 100 ppm to about 800 ppm metal, about 150 toabout 800 ppm metal, or about 200 ppm to about 800 metals. Inapproaches, the metals are preferably calcium and/or magnesium and mostpreferably, calcium provided by phenates and/or sulfonates and, mostpreferably, overbased calcium sulfonates.

In one approach, suitable detergents in the system may include alkali oralkaline earth metal salts, e.g., calcium or magnesium, of petroleumsulfonic acids and long chain mono- or di-alkylaryl sulfonic acids withthe aryl group being benzyl, tolyl, and xylyl and/or various phenates orderivatives of phenates. Examples of suitable detergents include, butare not limited to low-based/neutral and overbased variations of thefollowing detergents: calcium phenates, calcium sulfur containingphenates, calcium sulfonates, calcium calixarates, calcium salixarates,calcium salicylates, calcium carboxylic acids, calcium phosphorus acids,calcium mono- and/or di-thiophosphoric acids, calcium alkyl phenols,calcium sulfur coupled alkyl phenol compounds, calcium methylene bridgedphenols, magnesium phenates, magnesium sulfur containing phenates,magnesium sulfonates, magnesium calixarates, magnesium salixarates,magnesium salicylates, magnesium carboxylic acids, magnesium phosphorusacids, magnesium mono- and/or di-thiophosphoric acids, magnesium alkylphenols, magnesium sulfur coupled alkyl phenol compounds, magnesiummethylene bridged phenols, sodium phenates, sodium sulfur containingphenates, sodium sulfonates, sodium calixarates, sodium salixarates,sodium salicylates, sodium carboxylic acids, sodium phosphorus acids,sodium mono- and/or di-thiophosphoric acids, sodium alkyl phenols,sodium sulfur coupled alkyl phenol compounds, or sodium methylenebridged phenols.

The detergent additives may be neutral, low-based, or overbased. Asunderstood, overbased detergent additives are well-known in the art andmay be alkali or alkaline earth metal overbased detergent additives.Such detergent additives may be prepared by reacting a metal oxide ormetal hydroxide with a substrate and carbon dioxide gas. The substrateis typically an acid, for example, an acid such as an aliphaticsubstituted sulfonic acid, an aliphatic substituted carboxylic acid, oran aliphatic substituted phenol.

The term “overbased” relates to metal salts, such as metal salts ofsulfonates, carboxylates, salicylates and/or phenates, wherein theamount of metal present exceeds the stoichiometric amount. Such saltsmay have a conversion level in excess of 100 % (i.e., they may comprisemore than 100 % of the theoretical amount of metal needed to convert theacid to its “normal,” “neutral” salt). The expression “metal ratio,”often abbreviated as MR, is used to designate the ratio of totalchemical equivalents of metal in the overbased salt to chemicalequivalents of the metal in a neutral salt according to known chemicalreactivity and stoichiometry. In a normal or neutral salt, the MR is oneand in an overbased salt, MR, is greater than one. They are commonlyreferred to as overbased, hyperbased, or superbased salts and may besalts of organic sulfur acids, carboxylic acids, or phenols.

As used herein, the term “TBN” is used to denote the Total Base Numberin mg KOH/g as measured by the method of ASTM D2896. An overbaseddetergent of the lubricating oil composition may have a total basenumber (TBN) of about 200 mg KOH/gram or greater, or about 250 mgKOH/gram or greater, or about 350 mg KOH/gram or greater, or about 375mg KOH/gram or greater, or about 400 mg KOH/gram or greater. Theoverbased detergent may have a metal to substrate ratio of from 1.1:1,or from 2:1, or from 4:1, or from 5:1, or from 7:1, or from 10:1.

Examples of suitable overbased detergents include, but are not limitedto, overbased calcium phenates, overbased calcium sulfur containingphenates, overbased calcium sulfonates, overbased calcium calixarates,overbased calcium salixarates, overbased calcium salicylates, overbasedcalcium carboxylic acids, overbased calcium phosphorus acids, overbasedcalcium mono- and/or di-thiophosphoric acids, overbased calcium alkylphenols, overbased calcium sulfur coupled alkyl phenol compounds,overbased calcium methylene bridged phenols, overbased magnesiumphenates, overbased magnesium sulfur containing phenates, overbasedmagnesium sulfonates, overbased magnesium calixarates, overbasedmagnesium salixarates, overbased magnesium salicylates, overbasedmagnesium carboxylic acids, overbased magnesium phosphorus acids,overbased magnesium mono- and/or di-thiophosphoric acids, overbasedmagnesium alkyl phenols, overbased magnesium sulfur coupled alkyl phenolcompounds, or overbased magnesium methylene bridged phenols.

When a low-based or neutral detergent is incorporated into the detergentsystem, it generally has a TBN of up to 175 mg KOH/g, up to 150 mgKOH/g, up to 100 mg KOH/g, or up to 50 mg KOH/g. The low-based/neutraldetergent may include a calcium or magnesium-containing detergent.Examples of suitable low-based/neutral detergent include, but are notlimited to, calcium sulfonates, calcium phenates, calcium salicylates,magnesium sulfonates, magnesium phenates, and/or magnesium salicylates.

In some embodiments, the detergent used in the driveline fluids hereinis a neutral or low-base calcium sulfonate or phenate with a total basenumber of about 0 to about 100 and, in other approaches, about 0 toabout 50. In other approaches, the detergent used in the drivelinefluids herein is an overbased calcium sulfonate or phenate with a totalbase number of 150 to 400 and, in other approaches, about 200 to about350. In yet other approaches, the detergent used in the driveline fluidsherein may be a magnesium sulfonate or phenate, and when a magnesiumsulfonate is incorporated into the detergent system, it can be anoverbased detergent with a total base number of 300 to 500 and, in otherapproaches, about 350 to about 450. The above described TBN valuesreflect those of finished detergent components that have been diluted ina base oil.

In other embodiments, the TBN of the detergents herein may reflect aneat or non-diluted version of the detergent component. For example, thefluids herein may include neutral to low base calcium sulfonate as aneat (or non-diluted) additive having a TBN of 0 to about 80, and inother approaches, about 20 to about 80. Overbased calcium sulfonate orphenate as a neat additive may have a TBN of about 300 to about 450, andin other approaches, about 380 to about 420. Overbased magnesiumsulfonate as a neat additive may have a TBN of about 500 to about 700,and in other approaches, about 600 to about 700. Preferably, thedetergent systems herein include overbased calcium sulfonate detergentsproviding about 50 to about 800 ppm calcium.

Base Oil System: In other aspects or embodiments, the lubricating andcooling fluids of the disclosure herein includes a unique base oilsystem including (i) a first base oil of lubricating viscosity selectedfrom one or more API Group Ito Group V base oils blended with (ii)select amounts of ester base oils. In some embodiments, the base oilsystems herein includes an API Group I, II, and/or III mineral base oilas the first base oil combined with the ester base oil. In anotherapproach, the base oil systems herein include an API Group IVpolyalphaolfin base oil as the first base oil combined with the esterbase oil. In any of the above embodiments, the base oil system includesat least about 20 weight percent of the ester base oil. As discussedmore below, the ester base oils of the fluids herein are a reactionproduct of one or more carboxylic acids or dicarboxylic acids having aspecific internal carbon chain length and one or more alcohols having aspecific linear or branched carbon chain length and provide a specifiedamount of ester functionality to the fluids. As such, when blended withthe detergent systems within the noted relationships of metal to estergroups, the drivelines and electric motors herein have very high levelsof magnet wire durability in context of breakdown voltage.

Ester Base Oil of the Base Oil System: One component of the lubricatingand cooling fluids herein is a base oil system including at least 20weight percent of the ester base oil. In one approach, the ester baseoil of the base oil system is a linear or branched monoester and, inother approaches, a linear or branched diester of dicarboxylic acids.This ester or diester may be a reaction product of one or morecarboxylic acids having an internal carbon chain length of 6 to 10carbons and one or more alcohols having a branched carbon chain lengthof 6 to 12 carbons, and in other approaches, a branched carbon chain of8 to 10 carbons, and in still yet other approaches, a branched carbonchain of 8 to 12 carbons as well as various mixtures thereof. Monoesterbase oils may have up to 20 carbons in the ester or alcohol groups.

Suitable ester base oils may include those obtained from the reaction ofselect carboxylic acid or dicarboxylic acids including sebacic acid,octanedioic acid; and/or adipic acid and the like and mixtures thereofwith a variety of linear or branched alcohols including4-methylpentanol, 3-methylpentanol, 2-methylheptanol, hexan-2-ol,6-methylheptanol, 5-methylheptanol, 4-methylheptanol, 3-methylpentanol,2-methylheptanol, octan-2-ol, 2-ethylhexanol, 4-ethylhexanol,8-methylnonanol, 7-methylnonanol, 6-methylnonanol, 5-methylnonanol,4-methylnonanol, 3-methylnonanol, 2-methylnonanol, decan2-ol,11-methyldodecanol and the like and mixtures thereof. Specific examplesof these diesters include bis(6-methylheptyl) hexanedioate,bis(8-methylnonyl) hexanedioate, bis(2-ethylhexyl) decanedioate,bis(2-ethylhexyl) hexanedioate, and the like, and combinations thereof.In one embodiment, the ester base oil is selected from diisooctyladipate, diisodecyl adipate, icosyl palmitate, or combinations thereof.In yet other embodiments, the ester base oil is a dibasic ester based onbis(6-methylhelptyl) adipate; a dibasic ester based on bi(8-methylnonyl)adipate; or a linear monoester having about 16 to 18 carbons in an acidmoiety and about 20 carbons in an alcohol moiety; or combinationsthereof

Such esters or diesters can be prepared by reacting the selectcarboxylic or dicarboxylic acid with the select alcohols (or mixturesthereof) as generally shown by the exemplary reaction scheme 1 belowresulting in the monoester or diester of Formula (I):

wherein R₁ includes m-2 carbons with, in some embodiments, m being aninteger from 6 to 10 and R₂ and R₃ are the same or different (in FormulaI) and includes a C6 to C12 branched alkyl chain, and in otherapproaches, a C8 to C10 branched alkyl chain, and in yet otherapproaches, a C8 to C12 branched alkyl chain, and in yet otherapproaches, a C6 to C10 branched alkyl chain, and n is an integer of 0or 1. (Specifically, Formula I is a monoester when n is 0 and a diesterwhen n is 1.) Preferably, the integer n is 1 and R₂ and R₃ are the sameor different and include C8 to C10 branched alkyl chains. In the contextof a monoester when n is 0, then R₃ and or R₂ may be up to 20 carbons,such as for instance, icosyl palmitate.

Diester base oils may have a mol percent of ester groups (—C(O)O—) ofabout 20 mol percent or more (such as about 20 to about 30 mol percentester groups or about 20 to about 25 mol percent ester groups) andmonoester base oils may have a mol percent of ester groups of about 8percent or less (such as about 6 to about 8 mol percent ester groups.)

First Base Oil of the Base Oil System: the base oil systems herein mayalso include one or more mineral oils and/or other synthetic oils as thefirst base oil component. As used herein, mineral oils and othersynthetic oils refers to oils categorized by the American PetroleumInstitute (API) category groups Group I to V oils. Examples of naturaloils include animal oils, vegetable oils (e.g. castor oil and lard oil),and mineral oils such as petroleum oils, paraffinic, or naphthenic oils.Oils derived from coal or shale are also suitable. The AmericanPetroleum Institute has categorized these different basestock types asfollows: Group I, greater than 0.03 wt percent sulfur, and/or less than90 vol percent saturates, viscosity index between 80 and 120 ; Group II,less than or equal to 0.03 wt percent sulfur, and greater than or equalto 90 vol percent saturates, viscosity index between 80 and 120 ; GroupIII, less than or equal to 0.03 wt percent sulfur, and greater than orequal to 90 vol percent saturates, viscosity index greater than 120 ;Group IV, all polyalphaolefins. Hydrotreated basestocks andcatalytically dewaxed basestocks, because of their low sulfur andaromatics content, generally fall into the Group II and Group IIIcategories. Polyalphaolefins (Group IV basestocks) are synthetic baseoils prepared from various alpha olefins and are substantially free ofsulfur and aromatics. Many Group V base oils are also true syntheticproducts and may include diesters, polyol esters, polyalkylene glycols,alkylated aromatics, polyphosphate esters, polyvinyl ethers, and/orpolyphenyl ethers, and the like.

Suitable oils may be derived from hydrocracking, hydrogenation,hydrofinishing, unrefined, refined, and re-refined oils, or mixturesthereof. Any oil blends of other base oils may be used so long as theydo not detract from the desired lubricating, electrical, and thermalproperties discussed above.

Unrefined oils are those derived from a natural, mineral, or syntheticsource with or without little further purification treatment. Refinedoils are similar to unrefined oils except that they have been treated byone or more purification steps, which may result in the improvement ofone or more properties. Examples of suitable purification techniques aresolvent extraction, secondary distillation, acid or base extraction,filtration, percolation, and the like. Oils refined to the quality of anedible oil may or may not beuseful. Edible oils may also be called whiteoils. In some embodiments, lubricant compositions are free of edible orwhite oils.

Re-refined oils are also known as reclaimed or reprocessed oils. Theseoils are obtained in a manner similar to that used to obtain refinedoils using the same or similar processes. Often these oils areadditionally processed by techniques directed to removal of spentadditives and oil breakdown products.

Mineral oils may include oils obtained by drilling, or from plants andanimals and mixtures thereof. For example, such oils may include, butare not limited to, castor oil, lard oil, olive oil, peanut oil, cornoil, soybean oil, and linseed oil, as well as mineral lubricating oils,such as liquid petroleum oils and solvent-treated or acid-treatedmineral lubricating oils of the paraffinic, naphthenic or mixedparaffinic-naphthenic types. Such oils may be partially orfully-hydrogenated, if desired. Oils derived from coal or shale may alsobe useful.

Useful other synthetic lubricating oils may include hydrocarbon oilssuch as polymerized, oligomerized, or interpolymerized olefins (e.g.,polybutylenes, polypropylenes, propyleneisobutylene copolymers);poly(1-hexenes), poly(1-octenes), trimers or oligomers of 1-decene,e.g., poly(1-decenes), such materials being often referred to asα-olefins, and mixtures thereof; alkyl-benzenes (e.g. dodecylbenzenes,tetradecylbenzenes, dinonylbenzenes, di-(2-ethylhexyl)-benzenes) ;polyphenyls (e.g., biphenyls, terphenyls, alkylated polyphenyls) ;diphenyl alkanes, alkylated diphenyl alkanes, alkylated diphenyl ethersand alkylated diphenyl sulfides and the derivatives, analogs andhomologs thereof or mixtures thereof.

Other synthetic lubricating oils include polyol esters, liquid esters ofphosphorus-containing acids (e.g., tricresyl phosphate, trioctylphosphate, and the diethyl ester of decane phosphonic acid), orpolymeric tetrahydrofurans. Synthetic oils may be produced byFischer-Tropsch reactions and typically may be hydroisomerizedFischer-Tropsch hydrocarbons or waxes. In an embodiment, oils may beprepared by a Fischer-Tropsch gas-to-liquid synthetic procedure as wellas from other gas-to-liquid oils.

The first base oil component of the base oil systems herein may have aKV100 (kinematic viscosity at 100° C.) as measured per ASTM D445-18 ofabout 2 to about 6 cSt, about 2 to about 4 cSt, about 2 to about 3 cSt.

The base oil systems used in the lubricating and cooling fluids hereinincludes a blend of the first base oil and the ester base oil discussedabove and, in some embodiments, includes a blend of one or more of aGroup Ito Group V base oils with the ester base oil. In otherembodiments, the first base oil(s) are one or more oils selected fromGroup Ito Group IV base oils, and, in yet another embodiments, the firstbase oil(s) are mineral base oils selected from Group I, Group II,and/or Group III or, alternatively, polyalphaolefin base oils selectedfrom Group IV.

In some approaches, for instance, the base oil systems herein suitablefor the magnet wire durability when combined with the noted detergentsystems include at least about 20 weight percent of the ester base oil,and in other approaches, about 20 to about 80 weight percent of theester base oil (based on the total weight of the base oil system), inyet other approaches, the base oil system is about 30 to about 75 weightpercent ester base oil, and in yet other approaches, about 35 to about73 weight percent ester base oil. In other approaches, or embodiments,the base oil system may include the ester base oil in amounts rangingfrom at least about 20 weight percent, at least about 25 weight percent,at least about 30 weight percent, at least about 35 weight percent, atleast about 40 weight percent, or at least about 50 weight percent toabout 80 weight percent or less, about 70 weight percent or less, about65 weight percent or less, or about 50 weight percent or less of thetotal base oil system.

In some approaches, for instance, the base oil system suitable for thelubricating compositions herein includes about 20 to about 80 weightpercent of a Group I, II, III, and/or IV oil as the first base oil(based on the total weight of the base oil system), in yet otherapproaches, the base oil system is about 60 to about 90 weight percentof the first base oil. In other approaches, or embodiments, the base oilsystems may include the first base oil in amounts ranging from at leastabout 50 weight percent, at least about 60 weight percent, at leastabout 70 weight percent, at least about 75 weight percent to about 80weight percent or less, or about 75 weight percent or less.

The finished lubricating and cooling fluids may include a major amountof the base oil system (that is the first base oil and the ester baseoil) and, in some approaches, may include about 70 to about 98 weightpercent of the base oil system, in other approaches, about 75 to about90 weight percent, and in yet other approaches, about 75 to about 85weight percent. In other approaches or embodiments, the lubricatingcompositions may include the base oil system in amounts ranging from atleast about 70 weight percent, at least about 75 weight percent, atleast about 80 weight percent, at least about 85 weight percent, or atleast about 90 weight percent to about 98 weight percent or less, about90 weight percent or less, about 85 weight percent or less, or about 80weight percent or less.

The base oil systems herein, in some approaches or embodiments, includethe blend of Group Ito Group V base oils as the first base oil and thenoted ester base oils may have a KV100 of about 2 to about 20 cSt, inother approaches, about 2 to about 10 cSt, about 2.5 to about 6 cSt, inyet other approaches, about 2.5 to about 3.5 cSt, and in otherapproaches about 2.5 to about 4.5cSt.

Lubricating and Cooling Fluids

The lubricant and cooling fluids of the present disclosure are suitablefor lubricating transmission and other components of an electric and/orhybrid-electric vehicle and include the above-described base oil systemcombined with one or more of the detergent additives providing theselect ratios of metals to mol percent of ester groups (that is, —C(O)O—groups) in the base oil system. Suitable ratios of metals to mol percentof ester groups in the base oil system may be about 70 or less, and inother approaches, about 10 to about 70 to achieve the high breakdownvoltage of the magnet wires. The lubricating oil composition may be adriveline oil, an automobile transmission fluid, an engine oil, and thelike and is particularly suitable for lubricating and contactingcomponents of electric and/or hybrid-electric vehicles including motors,generators, motor stators, and/or batteries.

In yet other approaches, the lubricating and cooling fluids may includeabout 30 to about 75 weight percent of the ester base oil as describedherein based on the total weight of the lubricating and cooling fluids.In other approaches, the lubricating and cooling fluids may include anamount of the ester base oil herein ranging from at least about 30weight percent, at least about 40 weight percent, at least about 50weight percent, at least about 60 weight percent, at least about 65weight percent, at least about 70 weight percent to less than about 80weight percent, less than about 75 weight percent, less than about 70weight percent, less than about 60 weight percent, less than about 50weight percent, or less than about 40 weight percent.

In further approaches, the lubricating oil compositions may also includeabout 40 to about 80 weight percent of the one or more mineral or othersynthetic (PAO) oil as the first base oil based on the total weight ofthe lubricating cooling fluids. The first base oil may include at leastone or more Group Ito Group V oils as discussed above as long as thelubricating compositions still achieve the desired characteristics asdiscussed throughout this disclosure.

As used herein, the terms “oil composition,” “lubrication composition,”“lubricating oil composition,” “lubricating oil,” “lubricantcomposition,” “fully formulated lubricant composition,” “lubricant,” and“lubricating and cooling fluid” are considered synonymous, fullyinterchangeable terminology referring to the finished lubricationproduct comprising a major amount of a base oil component plus minoramounts of the detergents and the other optional components.

The lubricants herein may also include other optional additives asneeded for particular applications so long as such additives do notdetract from the electrical and cooling properties as discussed herein.Several common optional additives are noted below:

Optional Additive Components

In addition to the base oils as described above, the lubricating oilcompositions herein may also include other additives to perform one ormore functions required of a lubricating fluid. Further, one or more ofthe mentioned additives may be multi-functional and provide otherfunctions in addition to or other than the function prescribed herein.

For example, the compositions herein may include one or more of at leastone component selected from the group consisting of a friction modifier,an air expulsion additive, an antioxidant, a corrosion inhibitor, a foaminhibitor, a seal-swell agent, a viscosity index improver, anti-rustagent, extreme pressure additives, and combinations thereof. Otherperformance additives may also include, in addition to those specifiedabove, one or more of metal deactivators, ashless TBN boosters,demulsifiers, emulsifiers, pour point depressants, and mixtures thereof.Typically, fully-formulated lubricating oils will contain one or more ofthese performance additives. Examples of some common optional additivecomponents are set forth below.

Viscosity Index Improvers:

In addition to the poly(meth)acrylate copolymer described above, thelubricating oil compositions herein also may optionally contain one ormore additional or supplemental viscosity index improvers. Suitablesupplemental viscosity index improvers may include polyolefins, olefincopolymers, ethylene/propylene copolymers, polyisobutenes, hydrogenatedstyrene-isoprene polymers, styrene/maleic ester copolymers, hydrogenatedstyrene/butadiene copolymers, hydrogenated isoprene polymers,alpha-olefin maleic anhydride copolymers, poly(meth)acrylates,polyacrylates, polyalkyl styrenes, hydrogenated alkenyl aryl conjugateddiene copolymers, or mixtures thereof. Viscosity index improvers mayinclude star polymers, comb polymers, and suitable examples may bedescribed in US Publication No. 2012/0101017 A1.

The lubricating oil compositions herein also may optionally contain oneor more dispersant viscosity index improvers in addition to the PMAviscosity index improver discussed above. Suitable dispersant viscosityindex improvers may include functionalized polyolefins, for example,ethylene-propylene copolymers that have been functionalized with thereaction product of an acylating agent (such as maleic anhydride) and anamine; poly(meth)acrylates functionalized with an amine, or esterifiedmaleic anhydride-styrene copolymers reacted with an amine.

The total amount of viscosity index improver and/or dispersant viscosityindex improver may be 0 wt. % to 20 wt. %, 0.1 wt. % to 15 wt. %, 0.25wt. % to 12 wt. %, or 0.5 wt. % to 10 wt. %, of the lubricatingcomposition.

Dispersants

The lubricant composition may include one or more select dispersants ormixtures thereof. Dispersants are often known as ashless-typedispersants because, prior to mixing in a lubricating oil composition,they do not contain ash-forming metals and they do not normallycontribute any ash when added to a lubricant. Ashless-type dispersantsare characterized by a polar group attached to a relatively highmolecular or weight hydrocarbon chain. Typical ashless dispersantsinclude N-substituted long chain alkenyl succinimides. N-substitutedlong chain alkenyl succinimides include polyisobutylene (PIB)substituents with a number average molecular weight of thepolyisobutylene substituent in a range of about 800 to about 2500 asdetermined by gel permeation chromatograph (GPC) using polystyrene (witha number average molecular weight of 180 to about 18,000) as thecalibration reference. The PIB substituent used in the dispersanttypically has a viscosity at 100° C. of about 2100 to about 2700 cSt asdetermined using ASTM D445-18. Succinimide dispersants and theirpreparation are disclosed, for instance in U.S. Pat. No. 7,897,696 andU.S. Pat. No. 4,234,435 which are incorporated herein by reference.Succinimide dispersants are typically an imide formed from a polyamine,typically a poly(ethyleneamine). The dispersants may include twosuccinimide moieties joined by a polyamine. The polyamine may be tetraethylene penta amine (TEPA), tri ethylene tetra amine (TETA), pentaethylene hexa amine (PEHA), other higher nitrogen ethylene diaminespecies and/or mixtures thereof The polyamines may be mixtures oflinear, branched and cyclic amines. The PIB substituents may be joinedto each succinimide moiety.

In some embodiments the lubricant composition comprises at least onepolyisobutylene succinimide dispersant derived from polyisobutylene withnumber average molecular weight in the range about 350 to about 5000, orabout 500 to about 3000, as measured by the GPC method described above.The polyisobutylene succinimide may be used alone or in combination withother dispersants.

In some embodiments, polyisobutylene (PIB), when included, may havegreater than 50 mol. %, greater than 60 mol. %, greater than 70 mol. %,greater than 80 mol. %, or greater than 90 mol. % content of terminaldouble bonds. Such a PIB is also referred to as highly reactive PIB(“HR-PIB”). HR-PIB having a number average molecular weight ranging fromabout 800 to about 5000 is suitable for use in embodiments of thepresent disclosure. Conventional non-highly reactive PIB typically hasless than 50 mol. %, less than 40 mol. %, less than 30 mol. %, less than20 mol. %, or less than 10 mol. % content of terminal double bonds.

An HR-PIB having a number average molecular weight ranging from about900 to about 3000, as measured by the GPC method described above, may besuitable. Such an HR-PIB is commercially available, or can besynthesized by the polymerization of isobutene in the presence of anon-chlorinated catalyst such as boron trifluoride, as described in U.S.Pat. No. 4,152,499 and U.S. Pat. No. 5,739,355. When used in theaforementioned thermal ene reaction, HR-PIB may lead to higherconversion rates in the reaction, as well as lower amounts of sedimentformation, due to increased reactivity.

In some embodiments the lubricant composition comprises at least onedispersant derived from polyisobutylene succinic anhydride. In anembodiment, the dispersant may be derived from a polyalphaolefin (PAO)succinic anhydride. In an embodiment, the dispersant may be derived fromolefin maleic anhydride copolymer. As an example, the dispersant may bedescribed as a poly-PIBSA. In an embodiment, the dispersant may bederived from an anhydride which is grafted to an ethylene-propylenecopolymer.

One class of suitable dispersants may be Mannich bases. Mannich basesare materials that are formed by the condensation of a higher molecularweight, alkyl substituted phenol, a polyalkylene polyamine, and analdehyde such as formaldehyde. Mannich bases are described in moredetail in U.S. Pat. No. 3,634,515.

A suitable class of dispersants may be high molecular weight esters orhalf ester amides.

The dispersants may also be post-treated by conventional methods byreaction with any of a variety of agents. Among these agents are boron,urea, thiourea, dimercaptothiadiazoles, carbon disulfide, aldehydes,ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides,maleic anhydride, nitriles, epoxides, carbonates, cyclic carbonates,hindered phenolic esters, and phosphorus compounds. U.S. Pat. Nos.7,645,726; 7,214,649; and 8,048,831 describes some suitablepost-treatment methods and post-treated products.

Suitable boron compounds useful in forming the dispersants hereininclude any boron compound or mixtures of boron compounds capable ofintroducing boron-containing species into the ashless dispersant. Anyboron compound, organic or inorganic, capable of undergoing suchreaction can be used. Accordingly, use can be made of boron oxide, boronoxide hydrate, boron trifluoride, boron tribromide, boron trichloride,HBF₄ boron acids such as boronic acid (e.g. alkyl-B(OH)₂ oraryl-B(OH)₂), boric acid, (i.e., H₃BO₃), tetraboric acid (i.e., H₂B₅O₇),metaboric acid (i.e., HBO₂), ammonium salts of such boron acids, andesters of such boron acids. The use of complexes of a boron trihalidewith ethers, organic acids, inorganic acids, or hydrocarbons is aconvenient means of introducing the boron reactant into the reactionmixture. Such complexes are known and are exemplified by borontrifluoride-diethyl ether, boron trifluoride-phenol, borontrifluoride-phosphoric acid, boron trichloride-chloroacetic acid, borontribromide-dioxane, and boron trifluoride-methyl ethyl ether.

Suitable phosphorus compounds for forming the dispersants herein includephosphorus compounds or mixtures of phosphorus compounds capable ofintroducing a. phosphorus-containing species into the ashlessdispersant. Any phosphorus compound, organic or inorganic, capable ofundergoing such reaction can thus be used. Accordingly, use can be madeof such inorganic phosphorus compounds as the inorganic phosphorusacids, and the inorganic phosphorus oxides, including their hydrates.Typical organic phosphorus compounds include full and partial esters ofphosphorus acids, such as the mono-, di-, and tri esters of phosphoricacid, thiophosphoric acid, dithiophosphoric acid, trithiophosphoric acidand tetra.thiophosphoric acid; the mono-, di-, and tri esters ofphosphorous acid, thiophosphorous acid, dithiophosphorous acid andtrithiophosphorous acid; the trihydrocarbyl phosphine oxides: thetrihydrocarbyl phosphine sulfides; the mono- and dihydrocarbylphosphonates, (RPO(OR)(OR″) where R and R″ are hydrocarbyl and R″ is ahydrogen atom or a hydrocarbyl group), and their mono-, di- and trithioanalogs; the mono- and dihydrocarbyl phosphonites, (RP(OR′)(OR″) where Rand R′ are hydrocarbyl and R″ is a hydrogen atom or a hydrocarbyl group)and their mono- and dithio analogs; and the like. Thus, use can be madeof such compounds as, for example, phosphorous acid (H₃PO₃, sometimesdepicted as H₂(HPO₃), and sometimes called ortho-phosphorous acid orphosphonic acid), phosphoric acid (H₃PO₄, sometimes calledorthophosphoric acid), hypophosphoric acid (H₄P₂O₆), metaphosphoric acid(HPO₃), pyrophosphoric acid (H₄P₂₀₇), hypophosphorous acid (H₃PO₂,sometimes called phosphinic acid), pyrophosphorous acid (H₄P₂O₅,sometimes called pyrophosphonic acid), phosphinous acid (H₃PO),tripolyphosphoric acid (H₅P₃O₁₀), tetrapolyphosphoric acid (H₅P₄O₁₃),trimetaphosphoric acid (H₃P₃O₉), phosphorus trioxide, phosphorustetraoxide, phosphorus pentoxide, and the like. Partial or total sulfuranalogs such as phosphorotetrathioic acid (H₃PS₄), phosphoromonothioicacid (H₃PO₃S), phosphorodithioic acid (H₃PO₂S₂), phosphorotrithioic acid(H₃POS₃), phosphorus sesquisulfide, phosphorus heptasulfide, andphosphorus pentasulfide (P₂S₅, sometimes referred to as P₄S₁₀) can alsobe used in forming dispersants for this disclosure. Also usable are theinorganic phosphorus halide compounds such as PCl₃, PBr₃, POlC₃, PSCl₄,etc.

Likewise use can be made of such organic phosphorus compounds as mono-,di-, and triesters of phosphoric acid (e.g., trihydrocarbyl phosphates,dihydrocarbyl monoacid phosphates, monohydrocarbyl diacid phosphates,and mixtures thereof), mono-, di-, and triesters of phosphorous acid(e.g., trihydrocarbyl phosphites, dihydrocarbyl hydrogen phosphites,hydrocarbyl diacid phosphites, and mixtures thereof), esters ofphosphonic acids (both “primary”, RP(O(OR)₂, and “secondary”,R₃P(O)(OR)), esters of phosphinic acids, phosphonyl halides (e.g.,RP(OCl₂ and R₂P(OCl), halophosphites (e.g., (RO)PCl₂ and (RO)₂PCl),halophosphates (e.g., ROP(OCl₂ and (RO)₂P(O)Cl), tertiary pyrophosphateesters (e.g., (RO)₂P(O—O—P(O(OR)₂), and the total or partial sulfuranalogs of any of the foregoing organic phosphorus compounds, and thelike wherein each hydrocarbyl group contains up to about 100 carbonatoms, or up to about 50 carbon atoms, or up to about 24 carbon atoms,or up to about 12 carbon atoms. Also usable are the halophosphinehalides (e.g., hydrocarbyl phosphorus tetrahalides, dihydrocarbylphosphorus trihalides, and trihydrocarbyl phosphorus dihalides), and thehalophosphines (monohalophosphines and dihalophosphines).

The lubricants herein may include mixtures of one or more boronated andphosphorylated dispersants set forth above combined with non-boronatedand non-phosphorylated dispersants.

In one embodiment the lubricating oil composition may include at leastone borated dispersant, wherein the dispersant is the reaction productof an olefin copolymer or a reaction product of an olefin copolymer withsuccinic anhydride, and at least one polyamine. The ratio ofPIBSA:polyamine may be from 1:1 to 10:1, or 1:1 to 5:1, or 4:3 to 3:1,or 4:3 to 2:1. A particularly useful dispersant contains apolyisobutenyl group of the PIBSA having a number average molecularweight (Mn) in the range of from about 500 to 5000, as determined by theGPC method described above, and a (B) polyamine having a general formulaH₂N(CH₂)_(m)—NH(CH₂)_(m)]_(n)—NH₂, wherein m is in the range from 2 to 4and n is in the range of from 1 to 2.

In addition to the above, the dispersant may be post-treated with anaromatic carboxylic acid, an aromatic polycarboxylic acid, or anaromatic anhydride wherein all carboxylic acid or anhydride group(s) areattached directly to an aromatic ring. Such carboxyl-containing aromaticcompounds may be selected from 1,8-naphthalic acid or anhydride and1,2-naphthalenedicarboxylic acid or anhydride,2,3-naphthalenedicarboxylic acid or anhydride,naphthalene-1,4-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid,phthalic anhydride, pyromellitic anhydride, 1,2,4-benzene tricarboxylicacid anhydride, diphenic acid or anhydride, 2,3-pyridine dicarboxylicacid or anhydride, 3,4-pyridine dicarboxylic acid or anhydride,1,4,5,8-naphthalenetetracarboxylic acid or anhydride, perylene-3,4,9,10-tetracarboxylic anhydride, pyrene dicarboxylic acid or anhydride, andthe like. The moles of this post-treatment component reacted per mole ofthe polyamine may range from about 0.1:1 to about 2:1. A typical molarratio of this post-treatment component to polyamine in the reactionmixture may range from about 0.2:1 to about 2:1. Another molar ratio ofthis post-treatment component to the polyamine that may be used mayrange from 0.25:1 to about 1.5:1. This post-treatment component may bereacted with the other components at a temperature ranging from about140° to about 180° C.

Alternatively, or in addition to the post-treatment described above, thedispersant may be post-treated with a non-aromatic dicarboxylic acid oranhydride. The non-aromatic dicarboxylic acid or anhydride of may have anumber average molecular weight of less than 500, as measured by the GPCmethod described above. Suitable carboxylic acids or anhydrides thereofmay include, but are not limited to acetic acid or anhydride, oxalicacid and anhydride, malonic acid and anhydride, succinic acid andanhydride, alkenyl succinic acid and anhydride, glutaric acid andanhydride, adipic acid and anhydride, pimelic acid and anhydride,suberic acid and anhydride, azelaic acid and anhydride, sebacic acid andanhydride, maleic acid and anhydride, fumaric acid and anhydride,tartaric acid and anhydride, glycolic acid and anhydride,1,2,3,6-tetrahydronaphthalic acid and anhydride, and the like.

The non-aromatic carboxylic acid or anhydride is reacted at a molarratio with the polyamine ranging from about 0.1 to about 2.5 moles permole of polyamine. Typically, the amount of non-aromatic carboxylic acidor anhydride used will be relative to the number of secondary aminogroups in the polyamine. Accordingly, from about 0.2 to about 2.0 molesof the non-aromatic carboxylic acid or anhydride per secondary aminogroup in Component B may be reacted with the other components to providethe dispersant according to embodiments of the disclosure. Another molarratio of the non-aromatic carboxylic acid or anhydride to polyamine thatmay be used may range from 0.25:1 to about 1.5:1 moles of per mole ofpolyamine. The non-aromatic carboxylic acid or anhydride may be reactedwith the other components at a temperature ranging from about 140° toabout 180° C.

The weight % actives of the alkenyl or alkyl succinic anhydride can bedetermined using a chromatographic technique. This method is describedin column 5 and 6 in U.S. Pat. No. 5,334,321. The percent conversion ofthe polyolefin is calculated from the % actives using the equation incolumn 5 and 6 in U.S. Pat. No. 5,334,321.

The TBN of a suitable borated dispersant may be from about 10 to about65 mg KOH/gram composition on an oil-free basis, which is comparable toabout 5 to about 30 mg KOH/gram composition TBN if measured on adispersant sample containing about 50 % diluent oil.

Typically, the dispersants described above are provided in about 4.5 toabout 25 weight percent and, in other approaches, about 4.5 to about 12weight percent, and in yet other approaches, about 4.5 to about 7.7weight percent in the lubricant.

Extreme Pressure Agents

The lubricating oil compositions herein may also optionally contain oneor more extreme pressure agents. Extreme Pressure (EP) agents that aresoluble in the oil include sulfur- and chlorosulfur-containing EPagents, chlorinated hydrocarbon EP agents and phosphorus EP agents.Examples of such EP agents include chlorinated wax; organic sulfides andpolysulfides such as dibenzyldisulfide, bis(chlorobenzyl) disulfide,dibutyl tetrasulfide, sulfurized methyl ester of oleic acid, sulfurizedalkylphenol, sulfurized dipentene, sulfurized terpene, and sulfurizedDiels-Alder adducts; phosphosulfurized hydrocarbons such as the reactionproduct of phosphorus sulfide with turpentine or methyl oleate;phosphorus esters such as the dihydrocarbyl and trihydrocarbylphosphites, e.g., dibutyl phosphite, diheptyl phosphite, dicyclohexylphosphite, pentylphenyl phosphite; dipentylphenyl phosphite, tridecylphosphite, distearyl phosphite and polypropylene substituted phenylphosphite; metal thiocarbamates such as zinc dioctyldithiocarbamate andbarium heptylphenol diacid; amine salts of alkyl and dialkylphosphoricacids, including, for example, the amine salt of the reaction product ofa dialkyldithiophosphoric acid with propylene oxide; and mixturesthereof.

The extreme pressure agents may be present in amount of, for example,from 0 to 3.0 wt. % or from 0.1 to 2.0 wt. %, based on the total weightof the lubricating oil composition.

Anti-Wear Agents: The lubricating oil compositions herein also mayoptionally contain one or more anti-wear agents. Examples of suitableantiwear agents include, but are not limited to, a metal thiophosphate;a metal dialkyldithiophosphate; a phosphoric acid ester or salt thereof;a phosphate ester(s); a phosphite; a phosphorus-containing carboxylicester, ether, or amide; a sulfurized olefin; thiocarbamate-containingcompounds including, thiocarbamate esters, alkylene-coupledthiocarbamates, and bis(S-alkyldithiocarbamyl) disulfides; and mixturesthereof. A suitable antiwear agent may be a molybdenum dithiocarbamate.The phosphorus containing antiwear agents are more fully described inEuropean Patent 612 839. The metal in the dialkyl dithio phosphate saltsmay be an alkali metal, alkaline earth metal, aluminum, lead, tin,molybdenum, manganese, nickel, copper, titanium, or zinc. A usefulantiwear agent may be zinc dialkyldithiophosphate.

Further examples of suitable antiwear agents include titanium compounds,tartrates, tartrimides, oil soluble amine salts of phosphorus compounds,sulfurized olefins, phosphites (such as dibutyl phosphite),phosphonates, thiocarbamate-containing compounds, such as thiocarbamateesters, thiocarbamate amides, thiocarbamic ethers, alkylene-coupledthiocarbamates, and bis(S-alkyldithiocarbamyl) disulfides. The tartrateor tartrimide may contain alkyl-ester groups, where the sum of carbonatoms on the alkyl groups may be at least 8. The antiwear agent may inone embodiment include a citrate.

The antiwear agent may be present in ranges including about 0 wt % toabout 15 wt %, in other approaches, about 0.01 wt % to about 10 wt %, inyet other approaches, about 0.05 wt % to about 5 wt %, or, in furtherapproaches, about 0.1 wt % to about 3 wt % of the lubricating oilcomposition.

Friction Modifiers

The lubricating oil compositions herein may also optionally contain oneor more friction modifiers. Suitable friction modifiers may comprisemetal containing and metal-free friction modifiers and may include, butare not limited to, imidazolines, amides, amines, succinimides,alkoxylated amines, alkoxylated ether amines, amine oxides, amidoamines,nitriles, betaines, quaternary amines, imines, amine salts, aminoguanidine, alkanolamides, phosphonates, metal-containing compounds,glycerol esters, sulfurized fatty compounds and olefins, sunflower oilother naturally occurring plant or animal oils, dicarboxylic acidesters, esters or partial esters of a polyol and one or more aliphaticor aromatic carboxylic acids, and the like.

Suitable friction modifiers may contain hydrocarbyl groups that areselected from straight chain, branched chain, or aromatic hydrocarbylgroups or mixtures thereof, and may be saturated or unsaturated. Thehydrocarbyl groups may be composed of carbon and hydrogen or heteroatoms such as sulfur or oxygen. The hydrocarbyl groups may range from 12to 25 carbon atoms. In some embodiments the friction modifier may be along chain fatty acid ester. In another embodiment the long chain fattyacid ester may be a mono-ester, or a di-ester, or a (tri)glyceride. Thefriction modifier may be a long chain fatty amide, a long chain fattyester, a long chain fatty epoxide derivatives, or a long chainimidazoline.

Other suitable friction modifiers may include organic, ashless(metal-free), nitrogen-free organic friction modifiers. Such frictionmodifiers may include esters formed by reacting carboxylic acids andanhydrides with alkanols and generally include a polar terminal group(e.g. carboxyl or hydroxyl) covalently bonded to an oleophilichydrocarbon chain. An example of an organic ashless nitrogen-freefriction modifier is known generally as glycerol monooleate (GMO) whichmay contain mono-, di-, and tri-esters of oleic acid. Other suitablefriction modifiers are described in U.S. Pat. No. 6,723,685.

Aminic friction modifiers may include amines or polyamines. Suchcompounds can have hydrocarbyl groups that are linear, either saturatedor unsaturated, or a mixture thereof and may contain from 12 to 25carbon atoms. Further examples of suitable friction modifiers includealkoxylated amines and alkoxylated ether amines. Such compounds may havehydrocarbyl groups that are linear, either saturated, unsaturated, or amixture thereof. They may contain from about 12 to about 25 carbonatoms. Examples include ethoxylated amines and ethoxylated ether amines.

The amines and amides may be used as such or in the form of an adduct orreaction product with a boron compound such as a boric oxide, boronhalide, metaborate, boric acid or a mono-, di- or tri-alkyl borate.Other suitable friction modifiers are described in U.S. Pat. No.6,300,291.

A friction modifier may optionally be present in ranges such as 0 wt. %to 6 wt. %, or 0.01 wt. % to 4 wt. %, or 0.05 wt. % to 2 wt. %.

Detergents

The lubricant composition also includes one or more select detergents ormixtures thereof to provide specific amounts of metal and soap contentto the lubricating composition. By one approach, the detergent is ametal containing detergent, such as neutral to overbased detergents.Suitable detergent substrates include phenates, sulfur containingphenates, sulfonates, calixarates, salixarates, salicylates, carboxylicacids, phosphorus acids, mono- and/or di-thiophosphoric acids, alkylphenols, sulfur coupled alkyl phenol compounds and methylene bridgedphenols. Suitable detergents and their methods of preparation aredescribed in greater detail in numerous patent publications, includingU.S. Pat. No. 7,732,390, and references cited therein. In one approach,the detergents are neutral to overbased sulfonates, phenates, orcarboxylates with an alkali metal or alkaline earth metal salt. Thedetergents may be linear or branched, such as linear or branchedsulfonates. Linear detergents are those that include a straight chainwith no side chains attached thereto and typically include carbon atomsbonded only to one or two other carbon atoms. Branched detergents arethose with one or more side chains attached to the molecule's backboneand may include carbon atoms bonded to one, two, three, or four othercarbon atoms. In one embodiment the sulfonate detergent may be apredominantly linear alkylbenzenesulfonate detergent. In someembodiments the linear alkyl (or hydrocarbyl) group may be attached tothe benzene ring anywhere along the linear chain of the alkyl group, butoften in the 2, 3, or 4 position of the linear chain, and in someinstances predominantly in the 2 position. In other embodiments, thealkyl (or hydrocarbyl) group may be branched, that is, formed from abranched olefin such as propylene or 1-butene or isobutene. Sulfonatedetergents having a mixture of linear and branched alkyl groups may alsobe used.

The detergent substrate may be salted with an alkali or alkaline earthmetal such as, but not limited to, calcium, magnesium, potassium,sodium, lithium, barium, or mixtures thereof. In some embodiments, thedetergent is free of barium. A suitable detergent may include alkali oralkaline earth metal salts of petroleum sulfonic acids and long chainmono- or di-alkylarylsulfonic acids with the aryl group being one ofbenzyl, tolyl, and xylyl.

Overbased detergent additives are well known in the art and may bealkali or alkaline earth metal overbased detergent additives. Suchdetergent additives may be prepared by reacting a metal oxide or metalhydroxide with a substrate and carbon dioxide gas. The substrate istypically an acid, for example, an acid such as an aliphatic substitutedsulfonic acid, an aliphatic substituted carboxylic acid, or an aliphaticsubstituted phenol. In general, the terminology “overbased” relates tometal salts, such as metal salts of sulfonates, carboxylates, andphenates, wherein the amount of metal present exceeds the stoichiometricamount. Such salts may have a conversion level in excess of 100 % (i.e.,they may comprise more than 100 % of the theoretical amount of metalneeded to convert the acid to its “normal,” “neutral” salt). Theexpression “metal ratio,” often abbreviated as MR, is used to designatethe ratio of total chemical equivalents of metal in the overbased saltto chemical equivalents of the metal in a neutral salt according toknown chemical reactivity and stoichiometry. In a normal or neutralsalt, the metal ratio is one and in an overbased salt, the MR, isgreater than one. Such salts are commonly referred to as overbased,hyperbased, or superbased salts and may be salts of organic sulfuracids, carboxylic acids, or phenols. The detergents may also exhibit atotal base number (TBN) of about 27 to about 400 and, in otherapproaches, about 200 to about 400.

In transmission fluids, the detergent provides less than about 455 ppmof the metal to the lubricant composition. Higher levels of metal resultin failures in one or more of the friction durability or wear tests setforth herein. In other approaches, the detergent provides about 0 toabout 281 ppm of metal. In yet other approaches, the detergent providesabout 0 to about 100 ppm metal to the lubricant composition.

The detergent also provides select levels of soap content to thelubricant composition and the provided soap amounts are balanced withthe level of metal such that if the metal is not within the desiredranges, then increasing soap content does not achieve desired results,which is discussed in more detail in the Examples herein. By oneapproach, the detergent provides about 0.02 to about 0.15 percent soapcontent to the final lubricating composition, such as sulfonate soap,phenate soap, and/or carboxylate soap. In other approaches, thedetergent provides about 0.02 to about 0.1 percent soap, and in yetother approaches, about 0.02 to about 0.05 percent soap.

Soap content generally refers to the amount of neutral organic acid saltand reflects a detergent's cleansing ability, or detergency, and dirtsuspending ability. The soap content can be determined by the followingformula, using an exemplary calcium sulfonate detergent (represented byRSO₃)_(v)Ca_(w)(CO₃)_(x)(Oh)_(y) with v, w, x, and y denoting the numberof sulfonate groups, the number of calcium atoms, the number ofcarbonate groups, and the number of hydroxyl groups respectively):

${{soap}{content}} = {\frac{{formula}{weight}{{of}\left\lbrack {\left( {{RS}O_{3}} \right)_{2}{Ca}} \right\rbrack}}{{effective}{formula}{weight}} \times 100}$

Effective formula weight is the combined weight of all the atoms thatmake up the formula (RSO₃)_(v)Ca_(w)(CO₃)_(x)(OH)_(y) plus that of anyother lubricant components. Further discussion on determining soapcontent can be found in FUELS AND LUBRICANTS HANDBOOK, TECHNOLOGY,PROPERTIES, PERFORMANCE, AND TESTING, George Totten, editor, ASTMInternational, 2003, relevant portions thereof incorporated herein byreference.

In some approaches, the metal containing detergent is not boronated suchthat the boron in the lubricant is solely provided by the dispersant.

The total amount of detergent that may be present in the lubricating oilcomposition may be from 0 wt. % to 2 wt. %, or from about 0 wt. % toabout 0.5 wt. %, or about 0 wt. % to about 0.15 wt.

Antioxidants

The lubricating oil compositions herein also may optionally contain oneor more antioxidants. Antioxidant compounds are known and include forexample, phenates, phenate sulfides, sulfurized olefins,phosphosulfurized terpenes, sulfurized esters, aromatic amines,alkylated diphenylamines (e.g., nonyl diphenylamine, di-nonyldiphenylamine, octyl diphenylamine, di-octyl diphenylamine),phenyl-alpha-naphthylamines, alkylated phenyl-alpha-naphthylamines,hindered non-aromatic amines, phenols, hindered phenols, oil-solublemolybdenum compounds, macromolecular antioxidants, or mixtures thereofAntioxidant compounds may be used alone or in combination.

Useful antioxidants may include diarylamines and high molecular weightphenols. In an embodiment, the lubricating oil composition may contain amixture of a diarylamine and a high molecular weight phenol, such thateach antioxidant may be present in an amount sufficient to provide up toabout 5%, by weight, based upon the final weight of the lubricating oilcomposition. In an embodiment, the antioxidant may be a mixture of 0.3to 2% diarylamine and 0.4 to 2% high molecular weight phenol, by weight,based upon the final weight of the lubricating oil composition.

The one or more antioxidant(s) may be present in ranges 0 wt. % to 5 wt.%, or 0.01 wt. % to 5 wt. %, or 0.1 wt. % to 3 wt. %, or 0.8 wt. % to 2wt. %, of the lubricating composition.

Corrosion Inhibitors

The automatic transmission lubricants may further include additionalcorrosion inhibitors (it should be noted that some of the othermentioned components may also have copper corrosion inhibitionproperties). Suitable additional inhibitors of copper corrosion includeether amines, polyethoxylated compounds such as ethoxylated amines andethoxylated alcohols, imidazolines, monoalkyl and dialkyl thiadiazole,and the like.

Thiazoles, triazoles and thiadiazoles may also be used in thelubricants. Examples include benzotriazole; tolyltriazole;octyltriazole; decyltriazole; dodecyltriazole; 2-mercaptobenzothiazole;2,5-dimercapto-1,3,4-thiadiazole; 2-mercapto-5-hydrocarbylthio-1,3,4-thiadiazoles; and2-mercapto-5-hydrocarbyldithio-1,3,4-thiadiazoles. In one embodiment,the thiadiazoles are 1,3,4-thiadiazoles. In another embodiment, thethiadiazoles are 2-hydrocarbyldithio-5-mercapto-1,3,4-dithiadiazoles. Anumber of the thiadiazoles are available as articles of commerce.

The corrosion inhibitor, if present, can be used in an amount sufficientto provide 0 wt. % to 5 wt. %, 0.01 wt. % tot 3 wt. %, 0.1 wt. % to 2wt. %, based upon the final weight of the lubricating oil composition.

Foam Inhibitors/Anti Foam Agents

Anti-foam/Surfactant agents may also be included in a fluid according tothe present disclosure. Various agents are known for such use. In oneembodiment, the agents are copolymers of ethyl acrylate and hexyl ethylacrylate, such as PC-1244, available from Solutia. In anotherembodiment, the agents are silicone fluids, such as 4% DCF. In anotherembodiment, the agents are mixtures of anti-foam agents.

Anti-Rust Agents

Various known anti-rust agents or additives are known for use intransmission fluids, and are suitable for use in the fluids according tothe present disclosure. The anti-rust agents include alkylpolyoxyalkylene ethers, such as Mazawet® 77, C-8 acids such as Neofat®8, oxyalkyl amines such as Tomah PA-14, 3-decyloxypropylamine, andpolyoxypropylene-polyoxyethylene block copolymers such as Pluronic®L-81.

Pour Point Depressants

Suitable pour point depressants may include polymethylmethacrylates ormixtures thereof. Pour point depressants may be present in an amountsufficient to provide from 0 wt. % to 1 wt. %, 0.01 wt. % to 0.5 wt. %,or 0.02 wt. % to 0.04 wt. %, based upon the total weight of thelubricating composition.

Seal-Swell Agents

The automatic transmission fluids of the present disclosure may furtherinclude seal swell agents. Seal swell agents such as esters, adipates,sebacates, azealates, phthalates, sulfones, alcohols, alkylbenzenes,substituted sulfolanes, aromatics, or mineral oils cause swelling ofelastomeric materials used as seals in engines and automatictransmissions.

Alcohol-type seal swell agents are generally low volatility linear alkylalcohols, such as decyl alcohol, tridecyl alcohol and tetradecylalcohol. Alkylbenzenes useful as seal swell agents includedodecylbenzenes, tetradecylbenzenes, dinonyl-benzenes,di(2-ethylhexyl)benzene, and the like. Substituted sulfolanes (e.g.those described in U.S. Pat. No. 4,029,588, incorporated herein byreference) are likewise useful as seal swell agents in compositionsaccording to the present disclosure. Mineral oils useful as seal swellagents in the present disclosure include low viscosity mineral oils withhigh naphthenic or aromatic content. Aromatic seal swell agents includethe commercially available Exxon Aromatic 200 ND seal swell agent.Commercially available examples of mineral oil seal swell agents includeExxon® Necton®-37 (FN 1380) and Exxon® Mineral Seal Oil (FN 3200).

Based on the above discussion, exemplary ranges of various lubricatingcomposition components are set forth in Table 1 below.

TABLE 1 Lubricant Composition for Electric and/or Hybrid-Electricapplications Suitable Ranges, Preferred Ranges, Component Weight PercentWeight Percent Ester base oil 20 to 80 30 to 80 Dispersants 4.5 to 25 2.0 to 12  Detergents 0 to 2  0 to 1.0 Friction Modifiers 0 to 6 0.01 to4   Other Viscosity Index Improvers  0 to 20  0 to 15 Antioxidants 0 to5 0.01 to 3   Rust inhibitors 0 to 1 0.005 to 0.5  Corrosion Inhibitors0 to 2 0.1 to 2  Anti-wear agents  0 to 15 0 to 3 Seal Swell Agents  0to 20  0 to 10 Antifoam Agents 0 to 1 0.005 to 0.8  Extreme pressureagents 0 to 3 0 to 2 First Base Oil(s) 40 to 80 50 to 80 Total 100 100

The percentages of each component above represent the weight percent ofeach component, based upon the weight of the total final lubricating oilcomposition. The balance of the lubricating oil composition consists ofone or more base oils as defined hereinabove. Additives used informulating the compositions described herein may be blended into thebase oil individually or in various sub-combinations. However, it may besuitable to blend all of the components concurrently using an additiveconcentrate (i.e., additives plus a diluent, such as a hydrocarbonsolvent).

DEFINITIONS

For purposes of this disclosure, the chemical elements are identified inaccordance with the Periodic Table of the Elements, CAS version,Handbook of Chemistry and Physics, 75th Ed. Additionally, generalprinciples of organic chemistry are described in “Organic Chemistry”,Thomas Sorrell, University Science Books, Sausolito: 1999, and “March'sAdvanced Organic Chemistry”, 5th Ed., Ed.: Smith, M. B. and March, J.,John Wiley & Sons, New York: 2001, the entire contents of which arehereby incorporated by reference.

As described herein, compounds may optionally be substituted with one ormore substituents, such as are illustrated generally above, or asexemplified by particular classes, subclasses, and species of thedisclosure.

Unless otherwise apparent from the context, the term “major amount” isunderstood to mean an amount greater than or equal to 50 weight percent,for example, from about 80 to about 98 weight percent relative to thetotal weight of the composition. Moreover, as used herein, the term“minor amount” is understood to mean an amount less than 50 weightpercent relative to the total weight of the composition.

As used herein, the term “hydrocarbyl group” or “hydrocarbyl” is used inits ordinary sense, which is well-known to those skilled in the art.Specifically, it refers to a group having a carbon atom directlyattached to the remainder of a molecule and having a predominantlyhydrocarbon character. Examples of hydrocarbyl groups include: (1)hydrocarbon substituents, that is, aliphatic (e.g., alkyl or alkenyl),alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic-,aliphatic-, and alicyclic-substituted aromatic substituents, as well ascyclic substituents wherein the ring is completed through anotherportion of the molecule (e.g., two substituents together form analicyclic radical); (2) substituted hydrocarbon substituents, that is,substituents containing non-hydrocarbon groups which, in the context ofthe description herein, do not alter the predominantly hydrocarbonsubstituent (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy,mercapto, alkylmercapto, nitro, nitroso, amino, alkylamino, andsulfoxy); (3) hetero-substituents, that is, substituents which, whilehaving a predominantly hydrocarbon character, in the context of thisdescription, contain other than carbon in a ring or chain otherwisecomposed of carbon atoms. Hetero-atoms include sulfur, oxygen, nitrogen,and encompass substituents such as pyridyl, furyl, thienyl, andimidazolyl. In general, no more than two, or as a further example, nomore than one, non-hydrocarbon substituent will be present for every tencarbon atoms in the hydrocarbyl group; in some embodiments, there willbe no non-hydrocarbon substituent in the hydrocarbyl group.

As used herein the term “aliphatic” encompasses the terms alkyl,alkenyl, alkynyl, each of which being optionally substituted as setforth below.

As used herein, an “alkyl” group refers to a saturated aliphatichydrocarbon group containing 1-12 (e.g., 1-8, 1-6, or 1-4) carbon atoms.An alkyl group can be straight or branched. Examples of alkyl groupsinclude, but are not limited to, methyl, ethyl, propyl, isopropyl,butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-heptyl, or2-ethylhexyl. An alkyl group can be substituted (i.e., optionallysubstituted) with one or more substituents such as halo, phospho,cycloaliphatic [e.g., cycloalkyl or cycloalkenyl], heterocycloaliphatic[e.g., heterocycloalkyl or heterocycloalkenyl], aryl, heteroaryl,alkoxy, aroyl, heteroaroyl, acyl [e.g., (aliphatic)carbonyl,(cycloaliphatic)carbonyl, or (heterocycloaliphatic)carbonyl], nitro,cyano, amido [e.g., (cycloalkylalkyl)carbonylamino, arylcarbonylamino,aralkylcarbonylamino, (heterocycloalkyl) carbonylamino,(heterocycloalkylalkyl) carbonylamino, heteroarylcarbonylamino,heteroaralkyl carbonylamino alkylaminocarbonyl, cycloalkylaminocarbonyl,heterocycloalkylaminocarbonyl, arylaminocarbonyl, orheteroarylaminocarbonyl], amino [e.g., aliphaticamino, cycloaliphaticamino, or heterocycloaliphaticamino], sulfonyl [e.g., aliphatic-SO₂-],sulfinyl, sulfanyl, sulfoxy, urea, thiourea, sulfamoyl, sulfamide, oxo,carboxy, carbamoyl, cycloaliphaticoxy, heterocyclo aliphaticoxy,aryloxy, heteroaryloxy, aralkyloxy, heteroarylalkoxy, alkoxycarbonyl,alkyl carbonyloxy, or hydroxy. Without limitation, some examples ofsubstituted alkyls include carboxyalkyl (such as HOOC-alkyl,alkoxycarbonylalkyl, and alkylcarbonyloxyalkyl), cyanoalkyl,hydroxyalkyl, alkoxyalkyl, acylalkyl, aralkyl, (alkoxyaryl)alkyl,(sulfonylamino) alkyl (such as (alkyl-SO₂-amino)alkyl), aminoalkyl,amidoalkyl, (cycloaliphatic)alkyl, or haloalkyl.

As used herein, an “alkenyl” group refers to an aliphatic carbon groupthat contains 2-8 (e.g., 2-12, 2-6, or 2-4) carbon atoms and at leastone double bond. Like an alkyl group, an alkenyl group can be straightor branched. Examples of an alkenyl group include, but are not limitedto allyl, isoprenyl, 2-butenyl, and 2-hexenyl. An alkenyl group can beoptionally substituted with one or more substituents such as halo,phospho, cycloaliphatic [e.g., cycloalkyl or cycloalkenyl],heterocycloaliphatic [e.g., heterocycloalkyl or hetero cycloalkenyl],aryl, heteroaryl, alkoxy, aroyl, heteroaroyl, acyl [e.g., (aliphatic)carbonyl, (cycloaliphatic)carbonyl, or (heterocycloaliphatic)carbonyl],nitro, cyano, amido [e.g., (cycloalkylalkyl)carbonylamino,arylcarbonylamino, aralkylcarbonylamino, (hetero cycloalkyl)carbonylamino, (heterocyclo alkylalkyl) carbonylamino,heteroarylcarbonylamino, heteroaralkylcarbonylamino alkylamino carbonyl,cycloalkylaminocarbonyl, hetero cyclo alkylaminocarbonyl,arylaminocarbonyl, or heteroarylaminocarbonyl], amino [e.g.,aliphaticamino, cycloaliphaticamino, heterocyclo aliphaticamino, oraliphaticsulfonylamino], sulfonyl [e.g., alkyl-SO₂—,cycloaliphatic-SO₂—, or aryl-SO₂—], sulfinyl, sulfanyl, sulfoxy, urea,thiourea, sulfamoyl, sulfamide, oxo, carboxy, carbamoyl,cycloaliphaticoxy, heterocycloaliphaticoxy, aryloxy, heteroaryloxy,aralkyloxy, heteroaralkoxy, alkoxycarbonyl, alkylcarbonyloxy, orhydroxy. Without limitation, some examples of substituted alkenylsinclude cyanoalkenyl, alkoxyalkenyl, acylalkenyl, hydroxyl alkenyl,aralkenyl, (alkoxyaryl) alkenyl, (sulfonylamino)alkenyl (such as(alkyl-SO₂-amino) alkenyl), aminoalkenyl, amidoalkenyl,(cycloaliphatic)alkenyl, or haloalkenyl.

As used herein, an “alkynyl” group refers to an aliphatic carbon groupthat contains 2-8 (e.g., 2-12, 2-6, or 2-4) carbon atoms and has atleast one triple bond. An alkynyl group can be straight or branched.Examples of an alkynyl group include, but are not limited to, propargyland butynyl. An alkynyl group can be optionally substituted with one ormore substituents such as aroyl, heteroaroyl, alkoxy, cycloalkyloxy,heterocycloalkyloxy, aryloxy, heteroaryloxy, aralkyl oxy, nitro,carboxy, cyano, halo, hydroxy, sulfo, mercapto, sulfanyl [e.g.,aliphaticsulfanyl or cycloaliphaticsulfanyl], sulfinyl [e.g.,aliphaticsulfinyl or cycloaliphaticsulfinyl], sulfonyl [e.g.,aliphatic-SO₂—, aliphaticamino-SO₂—, or cycloaliphatic- SO₂—], amido[e.g., aminocarbonyl, alkylaminocarbonyl, alkylcarbonylamino, cycloalkylaminocarbonyl, heterocycloalkylaminocarbonyl,cycloalkylcarbonylamino, arylamino carbonyl, arylcarbonylamino,aralkylcarbonylamino, (heterocycloalkyl) carbonylamino,(cycloalkylalkyl) carbonylamino, heteroaralkylcarbonylamino, heteroarylcarbonylamino or heteroaryl amino carbonyl], urea, thiourea, sulfamoyl,sulfamide, alkoxycarbonyl, alkyl carbonyloxy, cyclo aliphatic,heterocycloaliphatic, aryl, heteroaryl, acyl [e.g., (cycloaliphatic)carbonyl or (hetero cyclo aliphatic)carbonyl], amino [e.g.,aliphaticamino], sulfoxy, oxo, carboxy, carbamoyl, (cycloaliphatic)oxy,(heterocyclo aliphatic) oxy, or (heteroaryl)alkoxy.

As used herein, an “amino” group refers to —NR^(X)R^(Y) wherein each ofR^(X) and R^(Y) is independently hydrogen, alkyl, cycloakyl,(cycloalkyl)alkyl, aryl, aralkyl, heterocycloalkyl,(heterocycloalkyl)alkyl, heteroaryl, carboxy, sulfanyl, sulfinyl,sulfonyl, (alkyl)carbonyl, (cycloalkyl)carbonyl,((cycloalkyl)alkyl)carbonyl, arylcarbonyl, (aralkyl)carbonyl,(heterocyclo alkyl) carbonyl, ((heterocycloalkyl)alkyl)carbonyl,(heteroaryl)carbonyl, or (heteroaralkyl) carbonyl, each of which beingdefined herein and being optionally substituted. Examples of aminogroups include alkylamino, dialkylamino, or arylamino. When the term“amino” is not the terminal group (e.g., alkylcarbonylamino), it isrepresented by —NR^(X)—. R^(X) has the same meaning as defined above.

As used herein, a “cycloalkyl” group refers to a saturated carbocyclicmono- or bicyclic (fused or bridged) ring of 3-10 (e.g., 5-10) carbonatoms. Examples of cycloalkyl groups include cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, norbornyl, cubyl,octahydro-indenyl, decahydro-naphthyl, bicyclo[3.2.1]octyl,bicyclo[2.2.2] octyl, bicyclo[3.3.1]nonyl, bicyclo[3.3.2.]decyl,bicyclo[2.2.2]octyl, adamantyl, or((aminocarbonyl)cycloalkyl)cycloalkyl.

As used herein, a “heterocycloalkyl” group refers to a 3-10 memberedmono- or bicylic (fused or bridged) (e.g., 5- to 10-membered mono- orbicyclic) saturated ring structure, in which one or more of the ringatoms is a heteroatom (e.g., N, 0, S, or combinations thereof). Examplesof a heterocycloalkyl group include piperidyl, piperazyl,tetrahydropyranyl, tetrahydrofuryl, 1,4-dioxolanyl, 1,4-dithianyl,1,3-dioxolanyl, oxazolidyl, isoxazolidyl, morpholinyl, thiomorpholyl,octahydrobenzofuryl, octahydrochromenyl, octahydrothio chromenyl,octahydroindolyl, octahydropyrindinyl, decahydroquinolinyl,octahydrobenzo [b] thiopheneyl, 2-oxa-bicyclo[2.2.2]octyl,1-aza-bicyclo[2.2.2]octyl, 3-aza-bicyclo[3.2.1]octyl, and2,6-dioxa-tricyclo[3.3.1.0 ]nonyl. A monocyclic heterocycloalkyl groupcan be fused with a phenyl moiety to form structures, such astetrahydroisoquinoline, which would be categorized as heteroaryls.

A “heteroaryl” group, as used herein, refers to a monocyclic, bicyclic,or tricyclic ring system having 4 to 15 ring atoms wherein one or moreof the ring atoms is a heteroatom (e.g., N, O, S, or combinationsthereof) and in which the monocyclic ring system is aromatic or at leastone of the rings in the bicyclic or tricyclic ring systems is aromatic.A heteroaryl group includes a benzofused ring system having 2 to 3rings. For example, a benzofused group includes benzo fused with one ortwo 4 to 8 membered heterocycloaliphatic moieties (e.g., indolizyl,indolyl, isoindolyl, 3H-indolyl, indolinyl, benzo[b]furyl,benzo[b]thiophenyl, quinolinyl, or isoquinolinyl). Some examples ofheteroaryl are pyridyl, 1H-indazolyl, furyl, pyrrolyl, thienyl,thiazolyl, oxazolyl, imidazolyl, tetrazolyl, benzofuryl, isoquinolinyl,benzthiazolyl, xanthene, thioxanthene, phenothiazine, dihydroindole,benzo[1,3]dioxole, benzo[b]furyl, benzo[b] thiophenyl, indazolyl,benzimidazolyl, benzthiazolyl, puryl, cinnolyl, quinolyl, quinazolyl,cinnolyl, phthalazyl, quinazolyl, quinoxalyl, isoquinolyl,4H-quinolizyl, benzo-1,2,5-thiadiazolyl, or 1,8-naphthyridyl.

Without limitation, monocyclic heteroaryls include furyl, thiophenyl,2H-pyrrolyl, pyrrolyl, oxazolyl, thazolyl, imidazolyl, pyrazolyl,isoxazolyl, isothiazolyl, 1,3,4-thiadiazolyl, 2H-pyranyl, 4-H-pranyl,pyridyl, pyridazyl, pyrimidyl, pyrazolyl, pyrazyl, or 1,3,5-triazyl.Monocyclic heteroaryls are numbered according to standard chemicalnomenclature.

Without limitation, bicyclic heteroaryls include indolizyl, indolyl,isoindolyl, 3H-indolyl, indolinyl, benzo[b]furyl, benzo[b]thiophenyl,quinolinyl, isoquinolinyl, indolizinyl, isoindolyl, indolyl,benzo[b]furyl, bexo[b]thiophenyl, indazolyl, benzimidazyl,benzthiazolyl, purinyl, 4H-quinolizyl, quinolyl, isoquinolyl, cinnolyl,phthalazyl, quinazolyl, quinoxalyl, 1,8-naphthyridyl, or pteridyl.Bicyclic heteroaryls are numbered according to standard chemicalnomenclature.

As used herein, the term “treat rate” refers to the weight percent of acomponent in the lubricating and cooling fluids. For example, the treatrate of a specific polymer or additive in an oil composition is theweight percent of the polymer or additive in the composition: treatrate=(weight of the polymer/additive in an oil free basis)/(weight ofthe entire composition)×100 %. As mentioned above, treat rate of thepolymers/additives herein refers to the solids of the polymer/additiveabsent any oil or carrier fluid.

As used herein the term “viscosity index” is an arbitrary measure forthe change of viscosity with variations in temperature. The viscosityindex can be calculated using the Formula: VI=100*[(L−U)/(L−H)], where

-   -   L=kinematic viscosity at 40° C. of an oil of 0 viscosity index        having the same kinematic viscosity at 100° C. as the oil whose        viscosity index is to be calculated, mm²/s (cSt);    -   H=kinematic viscosity at 40° C. of an oil of 100 viscosity index        having the same kinematic viscosity at 100° C. as the oil whose        viscosity index is to be calculated mm²/s (cSt); and    -   U=kinematic viscosity at 40° C. of the oil whose viscosity index        is to be calculated mm²/s (cSt).

The weight average molecular weight (Mw) and the number averagemolecular weight (Mn) may be determined with a gel permeationchromatography (GPC) instrument obtained from Waters or the likeinstrument and the data processed with Waters Empower Software or thelike software. The GPC instrument may be equipped with a WatersSeparations Module and Waters Refractive Index detector (or the likeoptional equipment). The GPC operating conditions may include a guardcolumn, 4 Agilent PLgel columns (length of 300×7.5 mm; particle size of5μ, and pore size ranging from 100 -10000 Å) with the column temperatureat about 40° C. Un-stabilized HPLC grade tetrahydrofuran (THF) may beused as solvent, at a flow rate of 1.0 mL/min. The GPC instrument may becalibrated with commercially available poly(methyl methacrylate) (PMMA)standards having a narrow molecular weight distribution ranging from960-1,568,000 g/mol. The calibration curve can be extrapolated forsamples having a mass less than 500 g/mol. Samples and PMMA standardscan be in dissolved in THF and prepared at concentration of 0.1 to 0.5wt. % and used without filtration. GPC measurements are also describedin U.S. Pat. No. 5,266,223, which is incorporated herein by reference.The GPC method additionally provides molecular weight distributioninformation; see, for example, W. W. Yau, J. J. Kirkland and D. D. Bly,“Modem Size Exclusion Liquid Chromatography”, John Wiley and Sons, NewYork, 1979, also incorporated herein by reference.

As discussed, the lubricating and cooling fluids herein are particularlysuited for electric and hybrid-electric vehicles. Electric vehicles arethose including, but not limited to, a battery, such a lead battery, anickel-hydrogen battery, a lithium-ion battery, and/or a fuel cell, andequipped with an electric motor. Hybrid-electric vehicles are thoseemploying batteries, an electric motor, and an internal combustionengine in combination. The lubricants herein may be in contact withparts of the electric motor, magnet wires within the electric motor,and/or may be used for both the transmission and for cooling andlubricating the motor. For example, the lubricating compositions hereinmay be in contact with electrical windings and magnet wires found in thestator.

A better understanding of the present disclosure and its many advantagesmay be clarified with the following examples. The following examples areillustrative and not limiting thereof in either scope or spirit. Thoseskilled in the art will readily understand that variations of thecomponents, methods, steps, and devices described in these examples canbe used. Unless noted otherwise or apparent from the context ofdiscussion in the Examples below and throughout this disclosure, allpercentages, ratios, and parts noted in this disclosure are by weight.Unless otherwise described, exemplary reactions described herein andthroughout this disclosure were generally performed in a 500 mL flaskwith overhead stirring, a condenser, temperature probe, and nitrogensupply. When necessary, the reactions were heated using an isomantle.

EXAMPLES

Insulated magnet wires were evaluated for breakdown voltage after agingin Comparative and Inventive lubricating and cooling fluids. Breakdownvoltage was measured as the Dielectric Breakdown AC Voltage specified inSections 70 to 76 of ASTM D1676-17 using the parameters as specified inTable 9 thereof for 6 wire twists. Each wire was prepared pursuant tosection 3.8.4 of ANSI NEMA Magnet Wire standard 1000 -2018. The twistedwires were placed in glass containers and immersed in about 75 grams ofeither the Comparative or Inventive lubricating and cooling fluids andabout 1500 ppm of water. Each container was aged at about 150° C. for 5days. The water added to the container was to increase the severity ofthe test. After aging, samples were allowed to cool to room temperature.The wires were removed from the containers and washed with heptane fourtimes. The wires were allowed to air dry. The insulating material aroundeach wire was removed from about 1 millimeter from the tip of the wire.Electrodes were then connected to the exposed wire tips for testing.

The following ester base oils were tested in the base oil systems of theComparative and Inventive lubricating and cooling fluids. In each fluid,the base oil system comprised (i) one of the ester base oils describedbelow and (ii) at least one other API Group IV polyalphaolefin base oil.

-   -   Ester base oil 1 (E-1): dibasic ester based on        bis(6-methylheptyl) adipate was a branched diester having 6        internal carbons in the acid moiety and 8 carbons in the alcohol        moiety. This branched diester had a KV 100 C of about 2.7 cSt        and had about 23.7 mol percent of ester groups (ester groups        being —C(O)O— groups and E-1 has 2 such ester groups).    -   Ester base oil 2 (E-2): dibasic ester based on        bis(8-methylnonyl) adipate was a branched diester having 6        internal carbons in the acid moiety and 10 carbons in the        alcohol moiety. This branched diester had a KV 100 C of 3.5 cSt        and had about 20.6 mol percent of ester groups (ester groups        being —C(O)O— groups and E-2 has 2 such ester groups).    -   Ester base oil 3 (E-3): linear monoester having about 16 -18        carbons in the acid moiety and 20 linear carbons in the alcohol        moiety (C₁₆₋₁₈-alkyl-COO—C₂₀ alkyl). This monoester had a KV 100        C of about 5.4 cSt and had about 7.7 mol percent ester groups        (ester groups being —C(O)O— groups and E-3 has 1 such ester        group).

The following calcium or magnesium overbased detergents were tested inthe Comparative and Inventive lubricating and cooling fluids:

-   -   Detergent 1 (DET-1): overbased calcium sulfonate detergent        (approximately 300 TBN, 11.9% calcium, and 25% soap content).    -   Detergent 2 (DET-2): overbased magnesium sulfonate detergent        (approximately 400 TBN, 9.6% magnesium).

Each Comparative and Inventive fluid also included the same amounts andsame set of additional fluid additives, which included dispersants,friction modifiers, antioxidants, metal passivator, extreme pressureagents, antifoam agents, and demulsifier.

Example 1

An insulated 15 American Wire Gauge (AWG) magnet wire having a 200° C.thermal rating with a polyester (amide)(imide) inner insulationover-coated with polyamideimide outer insulation layer (wire A) was agedin the Comparative and Inventive fluids of Tables 2 to 4 below for 5days at 150° C. After aging, the wire was washed in heptane and thebreakdown voltage was measured as reported in each table and shown inthe graph of FIG. 1 . A second 15 AWG magnet wire having a 180° C.thermal rating with a single polyester insulation layer (wire B) wasalso tested for comparison in Table 2. The base oil systems included theester base oil and the PAO base oil set forth in each table.

TABLE 2 Lubricating and Cooling Fluids with Ester Base Oil-1 IngredientC-1 I-I I-2 I-3 I-4 I-5 C-2 Wire A A A A A A B Det-1 0.18% 0.18% 0.18%0.36% 0.54% — 0.36% Det-2 — — — — — 0.54% — E-1  9.0% 36.1% 72.2% 36.1%72.2% 36.1% 36.1% PAQ¹ 81.2% 54.1% 18.0% 54.1% 18.0% PAO² 53.8% 54.1% %ester base oil in the base oil   10%   40%   80%   40%   80%   40%   40%system kV 100C of Finished Fluid (cSt) 67.6 24.8 6.7 21.9 3.7 4.3 4.2TBN of Finished Fluid 2.5 2.4 2.4 2.9 3.4 4 2.2 Breakdown voltage (V)9,330 12,409 15,246 14,736 15,242 15,243 <1,000 Calcium (ppm) inFinished 214 214 214 428 642 — 428 Fluid* Magnesium (ppm) in Finished —— — — 518 — Fluid* Ratio of detergent metal to ester 90.3 22.6 11.3 45.133.9 54.6 45.2 groups in base oil system (ppm/% mols)** ¹PAO: 100 cSt atKV100 ²PAO: 4 cSt at KV100 *metal content was calculated from amounts ofcalcium or magnesium provided by Det-1 or Det 2. No other source ofcalcium or magnesium was present in the fluids. **Ratio of metal toester groups in base oil system is ppm of detergent metal divided by molpercent of ester groups in the base oil system (for instance, the ratiofor fluid C-1 was calculated from the 214 ppm calcium from the detergentand the 23.7 mol % of ester groups from the E-1 ester base oil includedat 10% in the base oil system or 214/(23.7% × 10%) = 90.3)

TABLE 3 Lubricating and Cooling Fluids with Ester Base Oil-2 IngredientC-3 I-6 I-7 Wire A A A Det-1 0.18% 0.18% 0.18% E-2  9.0% 36.1% 72.2%PAO¹ 81.2% 54.1% 18.0% % ester base oil in the base oil   10%   40%  80% system kV 100 C of Finished Fluid (cSt) 70.38 28.23 8.4 TBN ofFinished Fluid 2.4 2.5 2.4 Breakdown voltage (V) 9,259 12,979 14,583Calcium (ppm) in Finished 214 214 214 Fluid* Ratio detergent metal toester 104.0 26.0 13.0 groups in base oil system (ppm/% mols)** ¹PAO: 100cSt at kV 100 C *metal content was calculated from amounts of calciumprovided by Det-1. No other source of calcium was present in the fluids.**Ratio of metal to ester groups in base oil system is ppm of detergentmetal divided by mol percent of ester groups in the base oil system (forinstance, the ratio for fluid C-3 was calculated from the 214 ppmcalcium from the detergent and the 20.6 mol % of ester groups from theE-2 ester base oil included at 10% in the base oil system or 214/(20.6%× 10%) = 104.0)

TABLE 4 Lubricating and Cooling Fluids with Ester Base Oil-3 IngredientC-4 C-5 I-8 I-9 Wire A A A A Det-1 0.18% 0.18% 0.18% 0.18% E-3  9.0%18.0% 36.1% 72.2% PAO¹ 81.2% 72.2% 54.1% 18.04% % ester base oil in thebase oil   10%   20%   40%   80% system kV 100 C of Finished Fluid (cSt)73.0 56.6 33.4 11.65 TBN of finished Fluid 2.5 2.5 2.5 2.5 Breakdownvoltage 4,805 9,730 10,613 12,188 Calcium(ppm) in Finished 214 ppm 214ppm 214 ppm 214 ppm Fluid* Ratio detergent metal to ester 278.0 139.069.5 34.7 groups in base oil system (ppm/% mols)** ¹PAO: 100 cSt at kV100 C *metal content was calculated from amounts of calcium provided byDet-1. No other source of calcium was present in the fluids. **Ratio ofmetal to ester groups in base oil system is ppm of detergent metaldivided by mol percent of ester groups in the base oil system (forinstance, the ratio for fluid C-4 was calculated from the 214 ppmcalcium from the detergent and the 7.7 mol % of ester groups from theE-3 ester base oil included at 10% in the base oil system or 214/(7.7% ×10%) = 278.0)

FIG. 1 includes a chart of breakdown voltage relative to the ratio ofdetergent metals to the mol percent of ester groups (—C(O)O—) in thebase oil system. As shown in the box in the upper left corner, fluidswith a ratio of about 70 or less (or about 10 to about 70) when combinedwith wire A achieved high breakdown voltage of 10,000 volts or higher.

It is noted that, as used in this specification and the appended claims,the singular forms “a,” “an,” and “the,” include plural referents unlessexpressly and unequivocally limited to one referent. Thus, for example,reference to “an antioxidant” includes two or more differentantioxidants. As used herein, the term “include” and its grammaticalvariants are intended to be non-limiting, such that recitation of itemsin a list is not to the exclusion of other like items that can besubstituted or added to the listed items

For the purposes of this specification and appended claims, unlessotherwise indicated, all numbers expressing quantities, percentages orproportions, and other numerical values used in the specification andclaims, are to be understood as being modified in all instances by theterm “about.” Accordingly, unless indicated to the contrary, thenumerical parameters set forth in the following specification andattached claims are approximations that can vary depending upon thedesired properties sought to be obtained by the present disclosure. Atthe very least, and not as an attempt to limit the application of thedoctrine of equivalents to the scope of the claims, each numericalparameter should at least be construed in light of the number ofreported significant digits and by applying ordinary roundingtechniques.

It is to be understood that each component, compound, substituent orparameter disclosed herein is to be interpreted as being disclosed foruse alone or in combination with one or more of each and every othercomponent, compound, substituent or parameter disclosed herein.

It is further understood that each range disclosed herein is to beinterpreted as a disclosure of each specific value within the disclosedrange that has the same number of significant digits. Thus, for example,a range from 1 to 4 is to be interpreted as an express disclosure of thevalues 1, 2, 3 and 4 as well as any range of such values.

It is further understood that each lower limit of each range disclosedherein is to be interpreted as disclosed in combination with each upperlimit of each range and each specific value within each range disclosedherein for the same component, compounds, substituent or parameter.Thus, this disclosure to be interpreted as a disclosure of all rangesderived by combining each lower limit of each range with each upperlimit of each range or with each specific value within each range, or bycombining each upper limit of each range with each specific value withineach range. That is, it is also further understood that any rangebetween the endpoint values within the broad range is also discussedherein. Thus, a range from 1 to 4 also means a range from 1 to 3, 1 to2, 2 to 4, 2 to 3, and so forth.

Furthermore, specific amounts/values of a component, compound,substituent or parameter disclosed in the description or an example isto be interpreted as a disclosure of either a lower or an upper limit ofa range and thus can be combined with any other lower or upper limit ofa range or specific amount/value for the same component, compound,substituent or parameter disclosed elsewhere in the application to forma range for that component, compound, substituent or parameter.

While particular embodiments have been described, alternatives,modifications, variations, improvements, and substantial equivalentsthat are or can be presently unforeseen can arise to applicants orothers skilled in the art. Accordingly, the appended claims as filed andas they can be amended are intended to embrace all such alternatives,modifications variations, improvements, and substantial equivalents.

What is claimed is:
 1. A driveline for an electric or hybrid-electricvehicle, the driveline comprising: an electric motor including aninsulated magnet wire having an insulation coating thereon with athermal rating of about 190° C. to about 210° C.; a lubricating andcooling fluid in contact with the insulation coating of the insulatedmagnet wire of the electric motor; and wherein the lubricating andcooling fluid includes a detergent system providing at least about 50ppm metal to the fluid and a base oil system including a first base oilof lubricating viscosity blended with an ester base oil, wherein thebase oil system includes at least about 20 weight percent of the esterbase oil, and a ratio of the metal provided by the detergent system tomol percent of ester groups in the base oil system of the lubricatingand cooling fluid of about 70 or less.
 2. The driveline for a hybrid orhybrid-electric vehicle of claim 1, wherein the insulation coating ofthe magnet wire includes one or more layers and wherein the layer incontact with the lubricating and cooling fluid includes a polyamide, apolyimide, a poly(amide/imide), combinations thereof, blends thereof, orcopolymers thereof
 3. The driveline for a hybrid or hybrid-electricvehicle of claim 2, wherein the magnet wire has an AWG gauge of 14 to30.
 4. The driveline for a hybrid or hybrid-electric vehicle of claim 3,wherein the magnet wire is copper.
 5. The driveline for a hybrid orhybrid-electric vehicle of claim 1, wherein the insulated magnet wire incontact with the lubricating and cooling fluid has a breakdown voltageof about 10,000 volts or higher.
 6. The driveline for a hybrid orhybrid-electric vehicle of claim 1, wherein the ester base oil includesa branched diester.
 7. The driveline for a hybrid or hybrid-electricvehicle of claim 6, wherein the branched diester is a reaction productof one or more dicarboxylic acids having an internal carbon chain lengthof 6 to 10 and one or more alcohols having a branched carbon chainlength of 6 to 12 carbons.
 8. The driveline for a hybrid orhybrid-electric vehicle of claim 1, wherein the ester base oil includesa monoester and/or a diester having the structure of Formula I:

wherein R₁ is a carbon chain having m-2 carbons with m being an integerfrom 6 to 10, R₂ and R₃ are the same or different and include C8 to C20linear or branched alkyl chains, and n is an integer of 0 or
 1. 9. Thedriveline for a hybrid or hybrid-electric vehicle of claim 8, wherein nis 1 and R₂ and R₃ are the same or different and include C8 to C10branched alkyl chains.
 10. The driveline for a hybrid or hybrid-electricvehicle of claim 1, wherein the ester base oil is selected from adibasic ester based on bi(6-methylheptyl)adipate; a dibasic ester basedon bis(8-methylnonyl)adipate; or a linear monoester having about 16 toabout 18 carbons in an acid moiety thereof and about 20 linear carbonsin an alcohol moiety thereof or combinations thereof.
 11. The drivelinefor a hybrid or hybrid-electric vehicle of claim 1, wherein thedetergent system includes alkali or alkaline metal salts of phenates,sulfonates, calixarates, salixrates, salicylates, carboxylic acids,sulfurized derivatives thereof, or combinations thereof.
 12. Thedriveline for a hybrid or hybrid-electric vehicle of claim 11, whereinthe alkali or alkaline metal includes calcium, magnesium, potassium,sodium, lithium, barium, or mixtures thereof.
 13. The driveline for ahybrid or hybrid-electric vehicle of claim 1, wherein the detergentsystem provides no more than 800 ppm of the metal.
 14. The driveline fora hybrid or hybrid-electric vehicle of claim 1, wherein the first baseoil of the base oil system is a mineral or synthetic base oil.
 15. Thedriveline for a hybrid or hybrid-electric vehicle of claim 1, whereinthe first base oil of the base oil system is a polyalphaolefin.
 16. Adriveline for a hybrid or hybrid-electric vehicle, the drivelinecomprising: an electric motor including an insulated magnet wire havingan insulation coating thereon, wherein the insulation coating include apolyamide, a polyimide, a poly(amide/imide), a combination thereof,blends thereof, or copolymers thereof; a lubricating and cooling fluidin contact with the coating of the insulated magnet wire of the electricmotor; and wherein the lubricating and cooling fluid includes adetergent system providing at least about 50 ppm metal to the fluid anda base oil system including a first base oil of lubricating viscosityblended with an ester base oil, wherein the base oil system includes atleast about 20 weight percent of the ester base oil.
 17. A driveline fora hybrid or hybrid-electric vehicle of claim 16, further comprising aratio of the metal provided by the detergent system to the mol percentof ester groups in the base oil system of about 70 or less.
 18. Thedriveline for a hybrid or hybrid-electric vehicle of claim 16, whereinthe insulation coating of the magnet wire has a thermal rating of about190° C. to about 200° C.
 19. The driveline for a hybrid orhybrid-electric vehicle of claim 16, wherein the insulated magnet wirein contact with the lubricating and cooling fluid has a breakdownvoltage of about 10,000 volts or higher.
 20. The driveline for a hybridor hybrid-electric vehicle of claim 16, wherein the ester base oilincludes a branched diester.
 21. The driveline for a hybrid orhybrid-electric vehicle of claim 20, wherein the branched diester is areaction product of one or more dicarboxylic acids having an internalcarbon chain length of 6 to 10 and one or more alcohols having abranched carbon chain length of 6 to 12 carbons.
 22. The driveline for ahybrid or hybrid-electric vehicle of claim 16, wherein the ester baseoil includes a monoester and/or a diester having the structure ofFormula I:

wherein R₁ is a carbon chain having m-2 carbons with m being an integerfrom 6 to 10, R₂ and R₃ are the same or different and include C8 to C20linear or branched alkyl chains, and n is an integer of 0 or
 1. 23. Thedriveline for a hybrid or hybrid-electric vehicle of claim 22, wherein nis 1 and R₂ and R₃ are the same or different and include C8 to C10branched alkyl chains.
 24. The driveline for a hybrid or hybrid-electricvehicle of claim 16, wherein the ester base oil is selected from adibasic ester based on bi(6-methylheptyl)adipate; a dibasic ester basedon bis(8-methylnonyl)adipate; or a linear monoester having about 16 toabout 18 carbons in an acid moiety thereof and about 20 linear carbonsin an alcohol moiety thereof; or combinations thereof.
 25. The drivelinefor a hybrid or hybrid-electric vehicle of claim 16, wherein thedetergent system includes alkali or alkaline metal salts of phenates,sulfonates, calixarates, salixrates, salicylates, carboxylic acids,sulfurized derivatives thereof, or combinations thereof.
 26. Thedriveline for a hybrid or hybrid-electric vehicle of claim 25, whereinthe alkali or alkaline metal includes calcium, magnesium, potassium,sodium, lithium, barium, or mixtures thereof.
 27. The driveline for ahybrid or hybrid-electric vehicle of claim 16, wherein the detergentsystem provides no more than 800 ppm of the metal.